- Configuring IPX Routing
- Configuring IPX Enhanced IGRP
- Configuring IPX and SPX over WANs
- Controlling Access to IPX Networks
- Tuning IPX Network Performance
- Shutting Down an IPX Network
- Configuring IPX Accounting
- Configuring IPX Between LANs
- Configuring IPX Between VLANs
- Configuring IPX Multilayer Switching
- Monitoring and Maintaining the IPX Newtork
Configuring Novell IPX
Note 
Effective with Cisco IOS Release 15.1(3)S, 15.2(2)T, and 15.1(1)SY, this feature is not available in Cisco IOS software.
Cisco IOS software supports a variety of routing protocols. Novell Internetwork Packet Exchange (IPX) is derived from the Xerox Network Systems (XNS) Internet Datagram Protocol (IDP). This guide discusses Novell IPX network protocols for IP and IP routing.
This guide describes how to configure Novell Internetwork Packet Exchange (IPX) and provides configuration examples. For a complete description of the IPX commands in this chapter, refer to the Cisco IOS Novell IPX Command Reference publication. To locate documentation of other commands that appear in this chapter, use the command reference master index or search online.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for Configuring Novell IPX" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•Configuration Examples for Novell IPX
•Feature Information for Configuring Novell IPX
Information About Novell IPX
Novell Internetwork Packet Exchange (IPX) is derived from the Xerox Network Systems (XNS) Internet Datagram Protocol (IDP). IPX and XNS have the following differences:
•IPX and XNS do not always use the same Ethernet encapsulation format.
•IPX uses the Novell proprietary Service Advertising Protocol (SAP) to advertise special network services. File servers and print servers are examples of services that typically are advertised.
IPX uses delay (measured in ticks) while XNS uses hop count as the primary metric in determining the best path to a destination.
The Cisco implementation of the Novell IPX protocol is certified to provide full IPX routing functionality. The following section provides information about different IPX support and IPX addresses.
IPX MIB Support
Cisco supports the IPX MIB (currently, read-only access is supported). The IPX Accounting group represents one of the local Cisco-specific IPX variables we support. This group provides access to the active database that is created and maintained if IPX accounting is enabled on a router or access server.
IPX Enhanced IGRP Support
Cisco IOS software supports IPX Enhanced IGRP, which provides the following features:
•Automatic redistribution—IPX Routing Information Protocol (RIP) routes are automatically redistributed into Enhanced IGRP, and Enhanced IGRP routes are automatically redistributed into RIP. If desired, you can turn off redistribution. You also can completely turn off Enhanced IGRP and IPX RIP on the device or on individual interfaces.
•Increased network width—With IPX RIP, the largest possible width of your network is 15 hops. When Enhanced IGRP is enabled, the largest possible width is 224 hops. Because the Enhanced IGRP metric is large enough to support thousands of hops, the only barrier to expanding the network is the transport layer hop counter. Cisco works around this problem by incrementing the transport control field only when an IPX packet has traversed 15 routers, and the next hop to the destination was learned via Enhanced IGRP. When a RIP route is being used as the next hop to the destination, the transport control field is incremented as usual.
•Incremental SAP updates—Complete SAP updates are sent periodically on each interface until an Enhanced IGRP neighbor is found, and thereafter only when changes are made to the SAP table. This procedure works by taking advantage of the Enhanced IGRP reliable transport mechanism, which means that an Enhanced IGRP peer must be present for incremental SAPs to be sent. If no peer exists on a particular interface, periodic SAPs will be sent on that interface until a peer is found. This functionality is automatic on serial interfaces and can be configured on LAN media.
LANE Support
Cisco IOS software supports routing IPX between Ethernet-emulated LANs and Token Ring-emulated LANs. For more information on emulated LANs and routing IPX between them, refer to the "Configuring LAN Emulation" chapter of the Cisco IOS Switching Services Configuration Guide.
VLAN Support
Cisco IOS software supports routing IPX between VLANs. Users with Novell NetWare environments can configure any one of the four IPX Ethernet encapsulations to be routed using ISL encapsulation across VLAN boundaries. For more information on VLANs and routing IPX between them over ISL, refer to the "Configuring Routing Between VLANs with ISL Encapsulation" chapter of the Cisco IOS Switching Services Configuration Guide.
Multilayer Switching Support
Cisco IOS software supports IPX Multilayer Switching (MLS). For more information on IPX MLS, refer to the "Multilayer Switching" chapter of the Cisco IOS Switching Services Configuration Guide.
IPX Addresses
An IPX network address consists of a network number and a node number expressed in the format network.node.
Network Numbers
The network number identifies a physical network. It is a 4-byte (32-bit) quantity that must be unique throughout the entire IPX internetwork. The network number is expressed as hexadecimal digits. The maximum number of digits allowed is eight.
The Cisco IOS software does not require that you enter all eight digits; you can omit leading zeros.
Node Numbers
The node number identifies a node on the network. It is a 48-bit quantity, represented by dotted triplets of four-digit hexadecimal numbers.
If you do not specify a node number for a router to be used on WAN links, the Cisco IOS software uses the hardware MAC address currently assigned to it as its node address. This is the MAC address of the first Ethernet, Token Ring, or FDDI interface card. If there are no valid IEEE interfaces, the Cisco IOS software randomly assigns a node number using a number that is based on the system clock.
IPX Address Example
The following example shows how to configure an IPX network address:
4a.0000.0c00.23fe
In this example, the network number is 4a (more specifically, it is 0000004a), and the node number is 0000.0c00.23fe. All digits in the address are hexadecimal.
How to Configure Novell IPX
To configure IPX routing, perform the tasks in the following sections:
•Configuring IPX Routing (Required)
•Configuring IPX Enhanced IGRP (Optional)
•Configuring IPX and SPX over WANs (Optional)
•Controlling Access to IPX Networks (Optional)
•Tuning IPX Network Performance (Optional)
•Shutting Down an IPX Network (Optional)
•Configuring IPX Accounting (Optional)
•Configuring IPX Between LANs (Optional)
•Configuring IPX Between VLANs (Optional)
•Configuring IPX Multilayer Switching (Optional)
•Monitoring and Maintaining the IPX Newtork (Optional)
Configuring IPX Routing
You configure IPX routing by first enabling it on the router and then configuring it on each interface.
Optionally, you can route IPX on some interfaces and transparently bridge it on other interfaces. You can also route IPX traffic between routed interfaces and bridge groups, or route IPX traffic between bridge groups.
To configure IPX routing, perform the tasks in the following sections. The first two tasks are required; the rest are optional.
•Enabling IPX Routing (Required)
•Assigning Network Numbers to Individual Interfaces (Required)
•Enabling Concurrent Routing and Bridging (Optional)
•Configuring Integrated Routing and Bridging (Optional)
IPX Default Routes
In IPX, a default route is the network where all packets for which the route to the destination address is unknown are forwarded.
Original Routing Information Protocol (RIP) implementations allowed the use of network -2 (0xFFFFFFFE) as a regular network number in a network. With the inception of NetWare Link Services Protocol (NLSP), network -2 is reserved as the default route for NLSP and RIP. Both NLSP and RIP routers should treat network -2 as a default route. Therefore, you should implement network -2 as the default route regardless of whether you configure NLSP in your IPX network.
By default, Cisco IOS software treats network -2 as the default route. You should ensure that your IPX network does not use network -2 as a regular network. If, for some reason, you must use network -2 as a regular network, you can disable the default behavior. To do so, see the "Adjusting Default Routes" section later in this chapter.
For more background information on how to handle IPX default routes, refer to the Novell NetWare Link Services Protocol (NLSP) Specification, Revision 1.1 publication.
Enabling IPX Routing
The first step in enabling IPX routing is to enable it on the router. If you do not specify the node number of the router to be used on WAN links, the Cisco IOS software uses the hardware MAC address currently assigned to it as its node address. This is the MAC address of the first Ethernet, Token Ring, or FDDI interface card. If there are no valid IEEE interfaces, the Cisco IOS software randomly assigns a node number using a number that is based on the system clock.
The following steps explain how to enable IPX routing command in global configuration mode.
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx routing [node]
4. end
DETAILED STEPS
For an example of how to enable IPX routing, see the "IPX Routing Examples" section at the end of this chapter.
If you plan to use DECnet and IPX routing concurrently on the same interface, you should enable DECnet routing first, then enable IPX routing without specifying the optional MAC node number. If you enable IPX before enabling DECnet routing, routing for IPX will be disrupted because DECnet forces a change in the MAC-level node number.
Assigning Network Numbers to Individual Interfaces
After you have enabled IPX routing, you enable IPX routing on the individual interfaces by assigning network numbers to those interfaces.
You enable IPX routing on interfaces that support a single network or multiple networks.
When you enable IPX routing on an interface, you can also specify an encapsulation (frame type) to use for packets being sent on that network. Table 1 lists the encapsulation types you can use on IEEE interfaces and shows the correspondence between Cisco naming conventions and Novell naming conventions for the encapsulation types.
Note The SNAP encapsulation type is not supported and should not be configured on any IPX interfaces that are attached to a FDDI-Ethernet bridge.
Assigning Network Numbers to Individual Interfaces Task List
The following sections describe how to enable IPX routing on interfaces that support a single network and on those that support multiple networks. To enable IPX routing on an interface, you must perform one of the tasks:
•Assigning Network Numbers to Interfaces That Support a Single Network (Required)
•Assigning Network Numbers to Interfaces That Support Multiple Networks (Required)
•Setting the Encapsulation Type for Subinterfaces (Required)
Assigning Network Numbers to Interfaces That Support a Single Network
A single interface can support a single network or multiple logical networks. For a single network, you can configure any encapsulation type. Of course, it should match the encapsulation type of the servers and clients using that network number.
To assign a network number to an interface that supports a single network, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx network network [encapsulation encapsulation-type]
5. end
DETAILED STEPS
If you specify an encapsulation type, be sure to choose the one that matches the one used by the servers and clients on that network. Novell-ether or ARPA encapsulations cannot be used for FDDI-Ethernet bridged IPX traffic. Use SAP encapsulations on originating and destination IPX interfaces that are attached to the FDDI-Ethernet bridge. See Table 1 for a list of encapsulation types you can use on IEEE interfaces.
For an example of how to enable IPX routing, see the "IPX Routing: Examples" section at the end of this chapter.
Assigning Network Numbers to Interfaces That Support Multiple Networks
When assigning network numbers to an interface that supports multiple networks, you must specify a different encapsulation type for each network. Because multiple networks share the physical medium, the Cisco IOS software is allowed to identify the packets that belong to each network. For example, you can configure up to four IPX networks on a single Ethernet cable, because four encapsulation types are supported for Ethernet. Remember, the encapsulation type should match the servers and clients using the same network number. See Table 1 for a list of encapsulation types you can use on IEEE interfaces.
There are two ways to assign network numbers to interfaces that support multiple networks. You can use subinterfaces or primary and secondary networks.
Setting the Encapsulation Type for Subinterfaces
You typically use subinterfaces to assign network numbers to interfaces that support multiple networks.
A subinterface is a mechanism that allows a single physical interface to support multiple logical interfaces or networks. That is, several logical interfaces or networks can be associated with a single hardware interface. Each subinterface must use a distinct encapsulation, and the encapsulation must match that of the clients and servers using the same network number.
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number subinterface-number
4. ipx network network [encapsulation encapsulation-type]
5. end
DETAILED STEPS
Note You cannot configure more than 200 IPX interfaces on a router using the ipx network command.
To configure more than one subinterface, repeat these two steps. See Table 1 for a list of encapsulation types you can use on IEEE interfaces.
For examples of configuring multiple IPX networks on an interface, see the "IPX Routing on Multiple Networks: Examples" section at the end of this chapter.
Primary and Secondary Networks
When assigning network numbers to interfaces that support multiple networks, you can also configure primary and secondary networks.
The first logical network you configure on an interface is considered the primary network. Any additional networks are considered secondary networks. Again, each network on an interface must use a distinct encapsulation and it should match that of the clients and servers using the same network number.
Any interface configuration parameters that you specify on this interface are applied to all the logical networks. For example, if you set the routing update timer to 120 seconds, this value is used on all four networks.
To use primary and secondary networks to configure multiple IPX networks on an interface, use the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx network network [encapsulation encapsulation-type]
5. ipx network network [encapsulation encapsulation-type] [secondary]
6. end
DETAILED STEPS
To configure more than one secondary network, repeat these steps as appropriate. See Table 1 for a list of encapsulation types you can use on IEEE interfaces.
Note When enabling NLSP and configuring multiple encapsulations on the same physical LAN interface, you must use subinterfaces. You cannot use secondary networks.
Enabling Concurrent Routing and Bridging
You can route IPX on some interfaces and transparently bridge it on other interfaces simultaneously. To enable this type of routing, you must enable concurrent routing and bridging. To enable concurrent routing and bridging, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. bridge crb
4. end
DETAILED STEPS
Configuring Integrated Routing and Bridging
Integrated routing and bridging (IRB) enables a user to route IPX traffic between routed interfaces and bridge groups, or route IPX traffic between bridge groups. Specifically, local or unroutable traffic is bridged among the bridged interfaces in the same bridge group. Routable traffic is routed to other routed interfaces or bridge groups. Using IRB, you can do the following:
•Switch packets from a bridged interface to a routed interface
•Switch packets from a routed interface to a bridged interface
•Switch packets within the same bridge group
For more information about configuring integrated routing and bridging, refer to the "Configuring Transparent Bridging" chapter in the Cisco IOS Bridging and IBM Networking Configuration Guide.
Configuring IPX Enhanced IGRP
Enhanced IGRP is an enhanced version of the Interior Gateway Routing Protocol (IGRP) developed by Cisco. Enhanced IGRP uses the same distance vector algorithm and distance information as IGRP. However, the convergence properties and the operating efficiency of Enhanced IGRP have improved significantly over IGRP.
The convergence technology is based on research conducted at SRI International and employs an algorithm referred to as the Diffusing Update Algorithm (DUAL). This algorithm guarantees loop-free operation at every instant throughout a route computation, and allows all routers involved in a topology change to synchronize at the same time. Routers that are not affected by topology changes are not involved in recomputations. The convergence time with DUAL rivals that of any other existing routing protocol.
Enhanced IGRP Features
Enhanced IGRP offers the following features:
•Fast convergence—The DUAL algorithm allows routing information to converge as quickly as any currently available routing protocol.
•Partial updates—Enhanced IGRP sends incremental updates when the state of a destination changes, instead of sending the entire contents of the routing table. This feature minimizes the bandwidth required for Enhanced IGRP packets.
•Less CPU usage than IGRP—Full update packets need not be processed each time they are received.
•Neighbor discovery mechanism—This feature is a simple hello mechanism used to learn about neighboring routers. It is protocol-independent.
•Scaling—Enhanced IGRP scales to large networks.
Enhanced IGRP Components
Enhanced IGRP has four basic components discussed in the following sections:
Neighbor Discovery/Recovery
Neighbor discovery/recovery is the process that routers use to dynamically learn of other routers on their directly attached networks. Routers must also discover when their neighbors become unreachable or inoperative. The router achieves neighbor discovery/recovery with low overhead by periodically sending
Reliable Transport Protocol
The reliable transport protocol is responsible for guaranteed, ordered delivery of Enhanced IGRP packets to all neighbors. It supports intermixed transmission of multicast and unicast packets. Some Enhanced IGRP packets must be sent reliably, and others need not be. For efficiency, reliability is provided only when necessary. For example, on a multiaccess network that has multicast capabilities (such as Ethernet) it is not necessary to send hellos reliably to all neighbors individually. Therefore, Enhanced IGRP sends a single multicast hello with an indication in the packet informing the receivers that the packet need not be acknowledged. Other types of packets (such as updates) require acknowledgment, which is indicated in the packet. The reliable transport has a provision to send multicast packets quickly when there are unacknowledged packets pending. This provision helps ensure that convergence time remains low in the presence of varying speed links.
DUAL Finite-State Machine
The DUAL finite-state machine embodies the decision process for all route computations. It tracks all routes advertised by all neighbors. DUAL uses the distance information (known as a metric) to select efficient, loop-free paths. DUAL selects routes to be inserted into a routing table based on feasible successors. A successor is a neighboring router used for packet forwarding that has a least-cost path to a destination that is guaranteed not to be part of a routing loop. When there are no feasible successors but there are neighbors advertising the destination, a recomputation must occur. This is the process whereby a new successor is determined. The amount of time it takes to recompute the route affects the convergence time. Recomputation is processor-intensive. It is advantageous to avoid recomputation if it is not necessary. When a topology change occurs, DUAL will test for feasible successors. If there are feasible successors, it will use any it finds in order to avoid unnecessary recomputation.
Protocol-Dependent Modules
The protocol-dependent modules are responsible for network layer protocol-specific tasks. They are also responsible for parsing Enhanced IGRP packets and informing DUAL of the new information received. Enhanced IGRP asks DUAL to make routing decisions, but the results are stored in the IPX routing table. Also, Enhanced IGRP is responsible for redistributing routes learned by other IPX routing protocols.
IPX Enhanced IGRP Configuration Task List
To enable IPX Enhanced IGRP, perform the tasks in the following sections. Only the first task is required; the remaining tasks are optional.
•Enabling IPX Enhanced IGRP (Required)
•Customizing Link Characteristics (Optional)
•Customizing the Exchange of Routing and Service Information (Optional)
•Querying the Backup Server (Optional)
Enabling IPX Enhanced IGRP
To create an IPX Enhanced IGRP routing process, use the following commands beginning in global configuration mode and interface configuration mode respectively:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx router eigrp autonomous-system-number
4. interface type number
5. ipx network {network-number | all}
6. end
DETAILED STEPS
To associate multiple networks with an Enhanced IGRP routing process, you can repeat the preceding two steps.
For an example of how to enable Enhanced IGRP, see the "IPX Enhanced IGRP Example" section at the end of this chapter.
Customizing Link Characteristics
You might want to customize the Enhanced IGRP link characteristics. The following sections describe these customization tasks:
•Configuring the Percentage of Link Bandwidth Used by Enhanced IGRP (Optional)
•Configuring Maximum Hop Count (Optional)
•Adjusting the Interval Between Hello Packets and the Hold Time (Optional)
Configuring the Percentage of Link Bandwidth Used by Enhanced IGRP
By default, Enhanced IGRP packets consume a maximum of 50 percent of the link bandwidth, as configured with the bandwidth interface subcommand. If a different value is desired, use the ipx bandwidth-percent command. This command may be useful if a different level of link utilization is required, or if the configured bandwidth does not match the actual link bandwidth (it may have been configured to influence route metric calculations).
To configure the percentage of bandwidth that may be used by Enhanced IGRP on an interface, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx bandwidth-percent eigrp as-number percent
5. end
DETAILED STEPS
For an example of how to configure the percentage of Enhanced IGRP bandwidth, see the "IPX Enhanced IGRP Bandwidth Configuration Example" section at the end of this chapter.
Configuring Maximum Hop Count
Note Although adjusting the maximum hop count is possible, it is not recommended for Enhanced IGRP. We recommend that you use the default value for the maximum hop count of Enhanced IGRP.
By default, IPX packets whose hop count exceeds 15 are discarded. In larger internetworks, this maximum hop count may be insufficient. You can increase the hop count to a maximum of 254 hops for Enhanced IGRP. To modify the maximum hop count, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx maximum-hops hops
4. end
DETAILED STEPS
Adjusting the Interval Between Hello Packets and the Hold Time
You can adjust the interval between hello packets and the hold time.
Routers periodically send hello packets to each other to dynamically learn of other devices on their directly attached networks. Routers use this information to discover their neighbors and to discover when their neighbors become unreachable or inoperative.
By default, hello packets are sent every 5 seconds. The exception is on low-speed, non broadcast multiaccess (NBMA) media, where the default hello interval is 60 seconds. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. The default hello interval remains 5 seconds for high-speed NBMA networks.
Note For the purposes of Enhanced IGRP, Frame Relay and SMDS networks may or may not be considered to be NBMA. These networks are considered NBMA if the interface has not been configured to use physical multicasting; otherwise they are considered not to be NBMA.
You can configure the hold time on a specified interface for a particular Enhanced IGRP routing process designated by the autonomous system number. The hold time is advertised in hello packets and indicates to neighbors the length of time they should consider the sender valid. The default hold time is three times the hello interval, or 15 seconds.
On very congested and large networks, 15 seconds may not be sufficient time for all routers to receive hello packets from their neighbors. In this case, you may want to increase the hold time. To increase the hold time, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx hold-time eigrp autonomous-system-number seconds
5. end
DETAILED STEPS
To change the interval between hello packets, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx hello-interval eigrp autonomous-system-number seconds
5. end
DETAILED STEPS
Note Do not adjust the hold time without consulting with Cisco technical support.
Customizing the Exchange of Routing and Service Information
You might want to customize the exchange of routing and service information. The following sections describe these customization tasks:
•Redistributing Routing Information (Optional)
•Disabling Split Horizon (Optional)
•Controlling the Advertising of Routes in Routing Updates (Optional)
•Controlling the Processing of Routing Updates (Optional)
•Controlling SAP Updates (Optional)
•Controlling the Advertising of Services in SAP Updates (Optional)
•Controlling the Processing of SAP Updates (Optional)
Redistributing Routing Information
By default, the Cisco IOS software redistributes IPX RIP routes into Enhanced IGRP, and vice versa. To disable route redistribution, use the following command in IPX-router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx router eigrp number
4. no redistribute {connected | eigrp autonomous-system-number | rip | static | floating-static}
5. end
DETAILED STEPS
Disabling Split Horizon
Split horizon controls the sending of Enhanced IGRP update and query packets. If split horizon is enabled on an interface, these packets are not sent for destinations if this interface is the next hop to that destination.
By default, split horizon is enabled on all interfaces.
Split horizon blocks information about routes from being advertised by the Cisco IOS software out any interface from which that information originated. This behavior usually optimizes communication among multiple routers, particularly when links are broken. However, with non broadcast networks (such as Frame Relay and SMDS), situations can arise for which this behavior is less than ideal. For these situations, you can disable split horizon.
To disable split horizon, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx split-horizon eigrp autonomous-system-number
5. end
DETAILED STEPS
Note Split horizon cannot be disabled for RIP or SAP, only for Enhanced IGRP.
Controlling the Advertising of Routes in Routing Updates
To control which devices learn about routes, you can control the advertising of routes in routing updates. To control this advertising, use the following command in router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. router routing-type number
4. distribute-list access-list-number out [interface-name | routing-process]
5. end
DETAILED STEPS
Note Split horizon cannot be disabled for RIP or SAP, only for Enhanced IGRP.
Controlling the Processing of Routing Updates
To control the processing of routes listed in incoming updates, use the following command in router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. router routing-type number
4. distribute-list access-list-number in [interface-name]
5. end
DETAILED STEPS
Controlling SAP Updates
If IPX Enhanced IGRP peers are found on an interface, you can configure the Cisco IOS software to send SAP updates either periodically or when a change occurs in the SAP table. When no IPX Enhanced IGRP peer is present on the interface, periodic SAPs are always sent.
On serial lines, by default, if an Enhanced IGRP neighbor is present, the Cisco IOS software sends SAP updates only when the SAP table changes. On Ethernet, Token Ring, and FDDI interfaces, by default, the software sends SAP updates periodically. To reduce the amount of bandwidth required to send SAP updates, you might want to disable the periodic sending of SAP updates on LAN interfaces. This feature should only be disabled when all nodes out of this interface are Enhanced IGRP peers; otherwise, loss of SAP information on the other nodes will result.
To send SAP updates only when a change occurs in the SAP table, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx sap-incremental eigrp autonomous-system-number
5. end
DETAILED STEPS
To send SAP updates only when a change occurs in the SAP table and to send only the SAP changes, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx sap-incremental eigrp autonomous-system-number rsup-only
5. end
DETAILED STEPS
When you enable incremental SAP using the ipx sap-incremental eigrp rsup-only command, Cisco IOS software disables the exchange of route information via Enhanced IGRP for that interface.
To send periodic SAP updates, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx sap-incremental eigrp autonomous-system-number
5. end
DETAILED STEPS
For an example of how to configure SAP updates, see the"Enhanced IGRP SAP Update Examples" section at the end of this chapter.
To disable split horizon for incremental SAP, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx sap-incremental split-horizon
5. end
DETAILED STEPS
Controlling the Advertising of Services in SAP Updates
To control which devices learn about services, you can control the advertising of these services in SAP updates. To control this advertising, use the following command in ipx router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx router routing-type number
4. distribute-sap-list access-list-number out [interface-name | routing-process]
5. end
DETAILED STEPS
For a configuration example of controlling the advertisement of SAP updates, see the "Advertisement and Processing of SAP Update Examples" section at the end of this chapter.
Controlling the Processing of SAP Updates
To control the processing of routes listed in incoming updates, use the following command in ipx router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx router routing-type number
4. distribute-sap-list access-list-number in [interface-name]
5. end
DETAILED STEPS
For a configuration example of controlling the processing of SAP updates, see the "Advertisement and Processing of SAP Update Examples" section at the end of this chapter.
Querying the Backup Server
The backup server table is a table kept for each Enhanced IGRP peer. It lists the IPX servers that have been advertised by that peer. If a server is removed from the main server table at any time and for any reason, the Cisco IOS software examines the backup server table to learn if this just-removed server is known by any of the Enhanced IGRP peers. If it is, the information from that peer is advertised back into the main server table just as if that peer had re-advertised the server information to this router. Using this method to allow the router to keep the backup server table consistent with what is advertised by each peer means that only changes to the table must be advertised between Enhanced IGRP routers; full periodic updates need not be sent.
By default, the Cisco IOS software queries its own copy of the backup server table of each Enhanced IGRP neighbor every 60 seconds. To change this interval, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx backup-server-query-interval interval
4. end
DETAILED STEPS
Configuring IPX and SPX over WANs
You can configure IPX over dial-on-demand routing (DDR), Frame Relay, PPP, SMDS, and X.25 networks. For more information about dial-on-demand routing (DDR) refer to the Cisco IOS Dial Technologies Configuration Guide. For more information about Frame Relay, SMDS, and X.25 refer to the Cisco IOS Wide-Area Networking Configuration Guide.
When you configure IPX over PPP, address maps are not necessary for this protocol. Also, you can enable IPX header compression over point-to-point links to increase available useful bandwidth of the link and reduce response time for interactive uses of the link.
You can use fast-switching IPX serial interfaces configured for Frame Relay and SMDS, and you can use fast-switching Subnetwork Access Protocol (SNAP)-encapsulated packets over interfaces configured for ATM.
Additionally, you can configure the IPXWAN protocol.
For an example of how to configure IPX over a WAN interface, see the "IPX over a WAN Interface Example" section at the end of this chapter.
Configuring IPX over DDR
IPX sends periodic watchdog keepalive packets from servers to clients after a client session has been idle for approximately 5 minutes. On a DDR link, a call would be made every 5 minutes, regardless of whether there were data packets to send. You can prevent these calls from being made by configuring the Cisco IOS software to respond to the watchdog keepalive packets of a server on behalf of a remote client—sometimes referred to as spoofing the server. Spoofing makes a server view a client as always connected, even when it is not, thus reducing the number of available licenses. Users can set the duration of IPX watchdog spoofing and periodically disable it so that Novelle NetWare servers can clean up inactive connections.
When configuring IPX over DDR, you might want to disable the generation of these packets so that a call is not made every 5 minutes. A call made every 5 minutes is not an issue for the other WAN protocols, because they establish dedicated connections rather than establishing connections only as needed.
Use the ipx watchdog-spoof command to enable and set the duration of watchdog spoofing. You can specify the number of consecutive hours spoofing is to stay enabled and the number of minutes spoofing is to stay disabled. The server can clean up inactive connections when spoofing is disabled. Be sure that fast switching and autonomous switching are disabled on the serial interface before using this command.
To enable watchdog spoofing, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx watchdog-spoof [enable-time-hours disable-time-minutes]
5. end
DETAILED STEPS
To keep the serial interface idle when only watchdog packets are being sent, refer to the tasks described in the "Deciding and Preparing to Configure DDR" chapter of the Cisco IOS Dial Technologies Configuration Guide. For an example of configuring IPX over DDR, see the "IPX over DDR Example" section at the end of this chapter.
Configuring SPX Spoofing over DDR
Sequenced Packet Exchange (SPX) sends periodic keepalive packets between clients and servers. Similar to IPX watchdog packets, these are keepalive packets that are sent between servers and clients after the data has stopped being transferred. On pay-per-packet or byte networks, these packets can incur large customer telephone connection charges for idle time. You can prevent these calls from being made by configuring the Cisco IOS software to respond to the keepalive packets on behalf of a remote system.
When configuring SPX over DDR, you might want to disable the generation of these packets so that a call has the opportunity to go idle. Disabling the generation of packets may not be an issue for the other WAN protocols, because they establish dedicated connections rather than establishing connections only as needed.
To keep the serial interface idle when only keepalive packets are being sent, refer to the tasks described in the "Deciding and Preparing to Configure DDR" chapter of the Cisco IOS Dial Technologies Configuration Guide.
For an example of how to configure SPX spoofing over DDR, see the "IPX over DDR Example" section at the end of this chapter.
Configuring IPX Header Compression
You can configure IPX header compression over point-to-point links. With IPX header compression, a point-to-point link can compress IPX headers only, or the combined IPX and NetWare Core Protocol headers. Currently, point-to-point links must first negotiate IPX header compression via IPXCP or IXPWAN. The Cisco IOS software supports IPX header compression as defined by RFC 1553.
For details on configuring IPX header compression, refer to the "Configuring Medial-Independent PPP and Multilink PPP" chapter in the Cisco IOS Dial Technologies Configuration Guide.
Configuring the IPXWAN Protocol
The Cisco IOS software supports the IPXWAN protocol, as defined in RFC 1634. IPXWAN allows a router that is running IPX routing to connect via a serial link to another router, possibly from another manufacturer, that is also routing IPX and using IPXWAN.
IPXWAN is a connection startup protocol. Once a link has been established, IPXWAN incurs little or no overhead.
You can use the IPXWAN protocol over PPP. You can also use it over HDLC; however, the devices at both ends of the serial link must be Cisco routers.
To configure IPXWAN on a serial interface, use the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx network [number]
5. encapsulation ppp
6. ipx ipxwan [local-node {network-number | unnumbered} local-server-name retry-interval retry-limit]
7. ipx ipxwan error [reset | resume | shutdown]
8. ipx ipxwan static
9. end
DETAILED STEPS
Controlling Access to IPX Networks
To control access to IPX networks, first create access lists and then apply them to individual interfaces using filters.
Types of Access Lists
You can create the following IPX access lists to filter various kinds of traffic:
•Standard access list—Restricts traffic based on the source network number. You can further restrict traffic by specifying a destination address and a source and destination address mask. Standard IPX access lists use numbers from 800 to 899 or names to identify them.
•Extended access list—Restricts traffic based on the IPX protocol type. You can further restrict traffic by specifying source and destination addresses and address masks, and source and destination sockets. Extended IPX access lists use numbers from 900 to 999 or names to identify them.
•SAP access list—Restricts traffic based on the IPX SAP type. These lists are used for SAP filters and GNS response filters. Novell SAP access lists use numbers from 1000 to 1099 or names to identify them.
•IPX NetBIOS access list—Restricts IPX NetBIOS traffic based on NetBIOS names, not numbers.
Types of Filters
There are more than 14 different IPX filters that you can define for IPX interfaces. They fall into the following six groups:
•Generic filters—Control which data packets are routed in or out of an interface based on the source and destination addresses and IPX protocol type of the packet.
•Routing table filters—Control which RIP updates are accepted and advertised by the Cisco IOS software, and from which devices the local router accepts RIP updates.
•SAP filters—Control which SAP services the Cisco IOS software accepts and advertises and which GNS response messages it sends out.
•IPX NetBIOS filters—Control incoming and outgoing IPX NetBIOS packets.
•Broadcast filters—Control which broadcast packets are forwarded.
Table 2 summarizes the filters, the access lists they use, and the commands used to define the filters in the first five groups. Use the show ipx interfaces command to display the filters defined on an interface.
Implementation Considerations
Remember the following information when configuring IPX network access control:
•Access lists entries are scanned in the order you enter them. The first matching entry is used. To improve performance, we recommend that you place the most commonly used entries near the beginning of the access list.
•An implicit deny everything entry is defined at the end of an access list unless you include an explicit permit everything entry at the end of the list.
•For numbered access lists, all new entries to an existing list are placed at the end of the list. You cannot add an entry to the middle of a list. Consequently, if you have previously included an explicit permit everything entry, new entries will never be scanned. The solution is to delete the access list and reenter it with the new entries.
For named access lists, all new entries to an existing list are placed at the end of the list. You cannot add entries to the middle of a list. However, you can remove specific entries using the no deny and no permit commands, rather than deleting the entire access list.
•Do not set up conditions that result in packets getting lost. One way you can lose packets is when a device or interface is configured to advertise services on a network that has access lists that deny these packets.
Controlling Access to IPX Networks Task List
To control access to IPX networks, perform the required tasks in the following sections:
•Creating Access Lists (Required)
•Creating Filters (Required)
Creating Access Lists
You can create access lists using numbers or names. You can choose which method you prefer. If you use numbers to identify your access lists, you are limited to 100 access lists per filter type. If you use names to identify your access lists, you can have an unlimited number of access lists per filter type.
The following sections describe how to perform these tasks:
•Creating Access Lists Using Numbers (Optional)
•Creating Access Lists Using Names (Optional)
Creating Access Lists Using Numbers
To create access lists using numbers, use one or more of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. access-list access-list-number {deny | permit} source-network [source-node [source-node-mask]] [destination-network [destination-node [destination-node-mask]]]
4. access-list access-list-number {deny | permit} protocol [source-network [source-node [source-network-mask.source-node-mask]] source-socket [destination-network [destination-node [destination-network-mask.destination-node-mask] destination-socket] [log] [time-range time-range-name]
5. access-list access-list-number {deny | permit} network [.node] [network-mask.node-mask] [service-type [server-name]]
6. end
DETAILED STEPS
Once you have created an access list using numbers, apply it to the appropriate interfaces using filters as described in the "Creating Filters" section later in this chapter. Applying a filter will activate the access list.
Creating Access Lists Using Names
IPX named access lists allow you to identify IPX access lists with an alphanumeric string (a name) rather than a number. Using IPX named access lists allows you to maintain security by using a separate and easily identifiable access list for each user or interface. IPX named access lists also remove the limit of 100 lists per filter type.You can configure an unlimited number of the following types of IPX named access lists:
•Standard
•Extended
•SAP
•NetBIOS
If you identify your access list with a name rather than a number, the mode and command syntax are slightly different.
Implementation Considerations
Consider the following information before configuring IPX named access lists:
•Except for NetBIOS access lists, access lists specified by name are not compatible with releases prior to Cisco IOS Release 11.2(4)F.
•Access list names must be unique across all protocols.
•Except for NetBIOS access lists, numbered access lists are also available.
IPX Named Access List Configuration Task List
To configure IPX named access lists for standard, extended, SAP, NLSP route aggregation (summarization), or NetBIOS access lists, perform one or more of the tasks in the following sections:
•Creating a Named Standard Access List (Optional)
•Creating a Named Extended Access List (Optional)
•Creating a Named SAP Filtering Access List (Optional)
•Creating a NetBIOS Access List (Optional)
•Applying Time Ranges to Access Lists (Optional)
Creating a Named Standard Access List
To create a named standard access list, use the following commands beginning in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx access-list standard name
4. {deny | permit} source-network [.source-node [source-node-mask]] [destination-network [.destination-node [destination-node-mask]]]
5. exit
DETAILED STEPS
For an example of creating a named standard access list, see the "Standard Named Access List Example" section at the end of this chapter.
Creating a Named Extended Access List
To create a named extended access list, use the following commands beginning in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx access-list standard name
4. {deny | permit} protocol [source-network] [[[.source-node] source-node-mask] | [.source-node source-network-mask.source-node-mask]] [source-socket] [destination-network] [[[.destination-node] destination-node-mask] | [.destination-node destination-network-mask.destination-nodemask]] [destination-socket] [log] [time-range time-range-name]
5. exit
DETAILED STEPS
Creating a Named SAP Filtering Access List
To create a named access list for filtering SAP requests, use the following commands beginning in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx access-list standard name
4. {deny | permit} network [.node] [network-mask.node-mask] [service-type [server-name]]
5. exit
DETAILED STEPS
Creating a NetBIOS Access List
To create a NetBIOS access list, use one or more of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. netbios access-list host name {deny | permit} string
4. netbios access-list bytes name {deny | permit} offset byte-pattern
5. exit
DETAILED STEPS
Modifying IPX Named Access Lists
After you initially create an access list, you place any subsequent additions (possibly entered from the terminal) at the end of the list. In other words, you cannot selectively add access list command lines to the middle of a specific access list. However, you can use no permit and no deny commands to remove entries from a named access list.
Note When creating access lists, remember that, by default, the end of the access list contains an implicit deny statement for everything if it did not find a match before reaching the end.
For an example of creating a generic filter, see the "IPX Network Access Example" section at the end of this chapter.
Applying Named Access Lists to Interfaces
After creating an access list, you must apply it to the appropriate interface using filters as described in the "Creating Filters" section later in this chapter. Applying a filter will activate the access list.
Applying Time Ranges to Access Lists
It is now possible to implement access lists based on the time of day and week using the time-range command. To do so, first define the name of the time range and times of the day and week, then reference the time range by name in an access list to apply the restrictions of the time range to the access list.
Currently, IP and IPX named or numbered extended access lists are the only functions that can use time ranges. The time range allows the network administrator to define when the permit or deny statements in the access list are in effect. Prior to this time range feature, access list statements were always in effect once they were applied. The time-range keyword and argument are referenced in the named and numbered extended access list task tables in the previous sections, "Creating Access Lists Using Numbers" and "Creating Access Lists Using Names." The time-range command is configured in the "Performing Basic System Management" chapter of the Cisco IOS Configuration Fundamentals Configuration Guide. See the "IPX Network Access Example" section at the end of this chapter for a configuration example of IPX time ranges.
There are many possible benefits of time ranges, such as the following:
•The network administrator has more control over permitting or denying a user access to resources. These resources could be an application (identified by an IP address/mask pair and a port number), policy routing, or an on-demand link (identified as interesting traffic to the dialer).
•Network administrators can set time-based security policy, including:
Perimeter security using the Cisco IOS Firewall feature set or access lists
Creating Filters
Filters allow you to control which traffic is forwarded or blocked at the interfaces of the router. Filters apply specific numbered or named access lists to interfaces.
To create filters, perform the tasks in the following sections:
•Creating Generic Filters (Optional)
•Creating Filters for Updating the Routing Table (Optional)
•Creating SAP Filters (Optional)
•Creating GNS Response Filters (Optional)
•Creating GGS Response Filters (Optional)
•Creating IPX NetBIOS Filters (Optional)
•Creating Broadcast Message Filters (Optional)
Creating Generic Filters
Generic filters determine which data packets to receive from or send to an interface, based on the source and destination addresses, IPX protocol type, and source and destination socket numbers of the packet.
To create generic filters, first create a standard or an extended access list as described in the "Creating Access Lists" section earlier in this chapter and then apply a filter to an interface.
To apply a generic filter to an interface, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx access-group {access-list-number | name}[in | out]
5. end
DETAILED STEPS
You can apply only one input filter and one output filter per interface or subinterface. You cannot configure an output filter on an interface where autonomous switching is already configured. Similarly, you cannot configure autonomous switching on an interface where an output filter is already present. You cannot configure an input filter on an interface if autonomous switching is already configured on any interface. Likewise, you cannot configure input filters if autonomous switching is already enabled on any interface.
For an example of creating a generic filter, see the "IPX Network Access Examples" section at the end of this chapter.
Creating Filters for Updating the Routing Table
Routing table update filters control the entries that the Cisco IOS software accepts for its routing table, and the networks that it advertises in its routing updates.
To create filters to control updating of the routing table, first create a standard or an extended access list as described in the "Creating Access Lists" section earlier in this chapter and then apply one or more routing filters to an interface.
To apply routing table update filters to an interface, use one or more of the following commands in interface configuration or router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx access-group {access-list-number | name}
5. ipx output-network-filter {access-list-number | name}
6. distribute-list {access-list-number | name} out [interface-name | routing-process]
7. ipx router-filter {access-list-number | name}
8. end
DETAILED STEPS
Note The ipx output-network-filter command applies to the IPX RIP only. To control the advertising of routes when filtering routing updates in Enhanced IGRP, use the distribute-list out command. See the "Controlling the Advertising of Routes in Routing Updates" section earlier in this chapter for more information.
Creating SAP Filters
A common source of traffic on Novell networks is SAP messages, which are generated by NetWare servers and the Cisco IOS software when they broadcast their available services.
To control how SAP messages from network segments or specific servers are routed among IPX networks, first create a SAP filtering access list as described in the "Creating Access Lists" section earlier in this chapter and then apply one or more filters to an interface.
To apply SAP filters to an interface, use one or more of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx input-sap-filter [access-list-number | name]
5. ipx output-sap-filter [access-list-number | name]
6. ipx router-sap-filter [access-list-number | name]
7. end
DETAILED STEPS
You can apply one of each SAP filter to each interface.
For examples of creating and applying SAP filters, see the "SAP Input Filter Example" and "SAP Output Filter Example" sections at the end of this chapter.
Creating GNS Response Filters
To create filters for controlling which servers are included in the GNS responses sent by the Cisco IOS software, first create a SAP filtering access list as described in the "Creating Access Lists" section earlier in this chapter and then apply a GNS filter to an interface.
To apply a GNS filter to an interface, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx output-gns-filter {access-list-number | name}
5. end
DETAILED STEPS
Creating GGS Response Filters
To create filters for controlling which servers are included in the Get General Service (GGS) responses sent by the Cisco IOS software, first create a SAP filtering access list as described in the "Creating Access Lists" section earlier in this chapter and then apply a GGS filter to an interface.
Note Because GGS SAP response filters are applied ahead of output SAP filters, a SAP entry permitted to pass through the GGS SAP response filter can still be filtered by the output SAP filter.
To apply a GGS filter to an interface, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx output-ggs-filter
5. end
DETAILED STEPS
For an example of creating a GGS SAP response filter, see the "IPX Network Access: Examples" section at the end of this chapter.
Creating IPX NetBIOS Filters
The Novell IPX NetBIOS allows messages to be exchanged between nodes using alphanumeric names and node addresses. Therefore, the Cisco IOS software lets you filter incoming and outgoing NetBIOS FindName packets by the node name or by an arbitrary byte pattern (such as the node address) in the packet.
Note These filters apply to IPX NetBIOS FindName packets only. They have no effect on Logic Link Control, type 2 (LLC2) NetBIOS packets.
Implementation Considerations
Remember the following when configuring IPX NetBIOS access control:
•Host (node) names are case sensitive.
•Host and byte access lists can have the same names because the two types of lists are independent of each other.
•When nodes are filtered by name, the names in the access lists are compared with the destination name field for IPX NetBIOS "find name" requests.
•Access filters that filter by byte offset can have a significant impact on the packet transmission rate because each packet must be examined. You should use these access lists only when absolutely necessary.
•If a node name is not found in an access list, the default action is to deny access.
Configuring IPX NetBIOS Filters
To create filters for controlling IPX NetBIOS access, first create a NetBIOS access list as described in the "Creating Access Lists" section earlier in this chapter and then apply the access list to an interface.
To apply a NetBIOS access list to an interface, use one or more of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx netbios input-access-filter host name
5. ipx netbios input-access-filter bytes name
6. ipx netbios output-access-filter host name
7. ipx netbios output-access-filter bytes name
8. end
DETAILED STEPS
You can apply one of each of these four filters to each interface.
For an example of how to create filters for controlling IPX NetBIOS, see the "IPX NetBIOS Filter Examples" section at the end of this chapter.
Creating Broadcast Message Filters
Routers normally block all broadcast requests and do not forward them to other network segments, therefore preventing the degradation of performance inherent in broadcast traffic over the entire network. You can define which broadcast messages get forwarded to other networks by applying a broadcast message filter to an interface.
To create filters for controlling broadcast messages, first create a standard or an extended access list as described in the "Creating Access Lists" section earlier in this chapter and then apply a broadcast message filter to an interface.
To apply a broadcast message filter to an interface, use the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx helper-address network.node
5. ipx helper-list {access-list-number | name}
6. end
DETAILED STEPS
Note A broadcast message filter has no effect unless you have issued an ipx helper-address or an ipx type-20-propagation command on the interface to enable and control the forwarding of broadcast messages. These commands are discussed later in this chapter.
For examples of creating and applying broadcast message filters, see the "Helper Facilities to Control Broadcast: Examples" section at the end of this chapter.
Tuning IPX Network Performance
To tune IPX network performance, perform the tasks in one or more of the following sections:
•Controlling Novell IPX Compliance (Optional)
•Adjusting RIP and SAP Information (Optional)
•Configuring Load Sharing (Optional)
•Specifying the Use of Broadcast Messages (Optional)
•Disabling IPX Fast Switching (Optional)
•Adjusting the Route Cache (Optional)
•Adjusting Default Routes (Optional)
•Padding Odd-Length Packets (Optional)
Controlling Novell IPX Compliance
The Cisco implementation of the Novell IPX protocol is certified to provide full IPX router functionality, as defined by the Novell IPX Router Specification, version 1.10 publication published November 17, 1992.
To control compliance to Novell specifications, perform the tasks in the following sections:
•Controlling the Forwarding of Type 20 Packets (Optional)
•Controlling Interpacket Delay (Optional)
•Shutting Down an IPX Network (Optional)
•Achieving Full Novell Compliance (Optional)
Controlling the Forwarding of Type 20 Packets
NetBIOS over IPX uses Type 20 propagation broadcast packets flooded to all networks to get information about the named nodes on the network. NetBIOS uses a broadcast mechanism to get this information, because it does not implement a network layer.
Routers normally block all broadcast requests. By enabling Type 20 packet propagation, IPX interfaces on the router may accept and forward Type 20 packets.
How Type 20 Packet Propagation Works
When an interface configured for Type 20 propagation receives a Type 20 packet, Cisco IOS software processes the packet according to Novell specifications. Cisco IOS software propagates the packet to the next interface. The Type 20 packet can be propagated for up to eight hop counts.
Loop Detection and Other Checks
Before forwarding (flooding) the packets, the router performs loop detection as described by the IPX router specification.
You can configure the Cisco IOS software to apply extra checks to Type 20 propagation packets above and beyond the loop detection described in the IPX specification. These checks are the same ones that are applied to helpered all-nets broadcast packets. They can limit unnecessary duplication of Type 20 broadcast packets. The extra helper checks are as follows:
•Accept Type 20 propagation packets only on the primary network, which is the network that is the primary path back to the source network.
•Forward Type 20 propagation packets only via networks that do not lead back to the source network.
Although this extra checking increases the robustness of Type 20 propagation packet handling by decreasing the amount of unnecessary packet replication, it has the following two side effects:
•If Type 20 packet propagation is not configured on all interfaces, these packets might be blocked when the primary interface changes.
•It might be impossible to configure an arbitrary, manual spanning tree for Type 20 packet propagation.
Relationship Between Type 20 Propagation and Helper Addresses
You use helper addresses to forward non-Type 20 broadcast packets to other network segments. For information on forwarding other broadcast packets, see the "Using Helper Addresses to Forward Broadcast Packets" section later in this chapter.
You can use helper addresses and Type 20 propagation together in your network. Use helper addresses to forward non-Type 20 broadcast packets and use Type 20 propagation to forward Type 20 broadcast packets.
Type 20 Packets Configuration Task List
You can enable the forwarding of Type 20 packets on individual interfaces. Additionally, you can restrict the acceptance and forwarding of Type 20 packets. You can also choose to not comply with Novell specifications and forward Type 20 packets using helper addresses rather than using Type 20 propagation. The following sections describe these tasks:
•Enabling the Forwarding of Type 20 Packets (Optional)
•Restricting the Acceptance of Incoming Type 20 Packets (Optional)
•Restricting the Forwarding of Outgoing Type 20 Packets (Optional)
•Forwarding Type 20 Packets Using Helper Addresses (Optional)
Enabling the Forwarding of Type 20 Packets
By default, Type 20 propagation packets are dropped by the Cisco IOS software. You can configure the software to receive Type 20 propagation broadcast packets and forward (flood) them to other network segments, subject to loop detection.
To enable the receipt and forwarding of Type 20 packets, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx type-20-propagation
5. end
DETAILED STEPS
When you enable Type 20 propagation, Cisco IOS propagates the broadcast to the next interface up to eight hops.
Restricting the Acceptance of Incoming Type 20 Packets
For incoming Type 20 propagation packets, the Cisco IOS software is configured by default to accept packets on all interfaces enabled to receive Type 20 propagation packets. You can configure the software to accept packets only from the single network that is the primary route back to the source network, which means that similar packets from the same source that are received via other networks will be dropped.
Checking of incoming Type 20 propagation broadcast packets is done only if the interface is configured to receive and forward Type 20 packets.
To impose restrictions on the receipt of incoming Type 20 propagation packets in addition to the checks defined in the IPX specification, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx type-20-input-checks
4. end
DETAILED STEPS
Restricting the Forwarding of Outgoing Type 20 Packets
For outgoing Type 20 propagation packets, the Cisco IOS software is configured by default to send packets on all interfaces enabled to send Type 20 propagation packets, subject to loop detection. You can configure the software to send these packets only to networks that are not routes back to the source network. (The software uses the current routing table to determine routes.)
Checking of outgoing Type 20 propagation broadcast packets is done only if the interface is configured to receive and forward Type 20 packets.
To impose restrictions on the transmission of Type 20 propagation packets, and to forward these packets to all networks using only the checks defined in the IPX specification, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx type-20-output-checks
4. end
DETAILED STEPS
Forwarding Type 20 Packets Using Helper Addresses
You can also forward Type 20 packets to specific network segments using helper addresses rather than using the Type 20 packet propagation.
You may want to forward Type 20 packets using helper addresses when some routers in your network are running versions of Cisco IOS that do not support Type 20 propagation. When some routers in your network support Type 20 propagation and others do not, you can avoid flooding packets everywhere in the network by using helper addresses to direct packets to certain segments only.
Cisco IOS Release 9.1 and earlier versions do not support Type 20 propagation.
Note Forwarding Type 20 packets using helper addresses does not comply with the Novell IPX router specification.
To forward Type 20 packets addresses using helper addresses, use the following commands beginning in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx type-20-helpered
4. interface type number
5. ipx helper-address network.node
6. end
DETAILED STEPS
The Cisco IOS software forwards Type 20 packets to only those nodes specified by the ipx helper-address command.
Note Using the ipx type-20-helpered command disables the receipt and forwarding of Type 20 propagation packets as directed by the ipx type-20-propagation command.
Controlling Interpacket Delay
To control interpacket delay, you can use a combination of global configuration and interface configuration commands.
Use one or more of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx default-output-rip-delay delay
4. ipx default-triggered-rip-delay delay
5. ipx default-output-sap-delay delay
6. ipx default-triggered-sap-delay delay
7. end
DETAILED STEPS
Use one or more of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx output-rip-delay delay
5. ipx triggered-rip-delay delay
6. ipx output-sap-delay delay
7. ipx triggered-sap-delay delay
8. end
DETAILED STEPS
Note We recommend that you use the ipx output-rip-delay and ipx output-sap-delay commands on slower speed WAN interfaces. The default delay for Cisco IOS Release 11.1 and later versions is 55 milliseconds.
Shutting Down an IPX Network
To shut down an IPX network using a Novell-compliant method, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx down network
5. end
DETAILED STEPS
Convergence is faster when you shut down an IPX network using the ipx down command than when using the shutdown command.
Achieving Full Novell Compliance
To achieve full compliance on each interface configured for IPX, use the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx output-rip-delay delay
5. ipx output-sap-delay delay
6. ipx type-20-propagation
7. end
DETAILED STEPS
You can also globally set interpacket delays for multiple-packet RIP and SAP updates to achieve full compliance, eliminating the need to set delays on each interface. To set these interpacket delays, use the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx default-output-rip-delay delay
4. ipx default-output-sap-delay delay
5. end
DETAILED STEPS
Note The default delay for Cisco IOS Release 11.1 and later versions is 55 milliseconds.
Adjusting RIP and SAP Information
To adjust RIP and SAP information, perform one or more of the optional tasks in the following sections:
•Configuring Static Routes (Optional)
•Adjusting the RIP Delay Field (Optional)
•Controlling Responses to RIP Requests (Optional)
•Adjusting RIP Update Timers (Optional)
•Configuring RIP Update Packet Size (Optional)
•Configuring Static SAP Table Entries (Optional)
•Configuring the Queue Length for SAP Requests (Optional)
•Adjusting SAP Update Timers (Optional)
•Configuring SAP Update Packet Size (Optional)
•Enabling SAP-after-RIP (Optional)
•Disabling Sending of General RIP or SAP Queries (Optional)
•Controlling Responses to GNS Requests (Optional)
Configuring Static Routes
IPX uses RIP, Enhanced IGRP, or NLSP to determine the best path when several paths to a destination exist. The routing protocol then dynamically updates the routing table. However, you might want to add static routes to the routing table to explicitly specify paths to certain destinations. Static routes always override any dynamically learned paths.
Be careful when assigning static routes. When links associated with static routes are lost, traffic may stop being forwarded or traffic may be forwarded to a nonexistent destination, even though an alternative path might be available.
To add a static route to the routing table, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx route {network [network-mask] | default} {network.node | interface}[ticks] [hops]
4. end
DETAILED STEPS
You can configure static routes that can be overridden by dynamically learned routes. These routes are referred to as floating static routes. You can use a floating static route to create a path of last resort that is used only when no dynamic routing information is available.
Note By default, floating static routes are not redistributed into other dynamic protocols.
To add a floating static route to the routing table, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx route {network [network-mask] | default} {network.node | interface}[ticks] [hops]
4. end
DETAILED STEPS
Adjusting the RIP Delay Field
By default, all LAN interfaces have a RIP delay of 1 and all WAN interfaces have a RIP delay of 6. Leaving the delay at its default value is sufficient for most interfaces. However, you can adjust the RIP delay field by setting the tick count. To set the tick count, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx delay ticks
5. end
DETAILED STEPS
Controlling Responses to RIP Requests
To control responses to RIP requests, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx rip-response-delay ms
5. end
DETAILED STEPS
Adjusting RIP Update Timers
You can set the interval between IPX RIP updates on a per-interface basis. You can also specify the delay between the packets of a multiple-packet RIP update on a per-interface or global basis. Additionally, you can specify the delay between packets of a multiple-packet triggered RIP update on a per-interface or global basis.
You can set RIP update timers only in a configuration in which all routers are Cisco routers, or in which the IPX routers allow configurable timers. The timers should be the same for all devices connected to the same cable segment. The update value you choose affects internal IPX timers as follows:
•IPX routes are marked invalid if no routing updates are heard within three times the value of the update interval (3 * interval) and are advertised with a metric of infinity.
•IPX routes are removed from the routing table if no routing updates are heard within four times the value of the update interval (4 * interval).
•If you define a timer for more than one interface in a router, the granularity of the timer is determined by the lowest value defined for one of the interfaces in the router. The router "wakes up" at this granularity interval and sends out updates as appropriate. For more information about granularity, refer to the "Novell IPX Commands" chapter in the Cisco IOS AppleTalk and Novell IPX Command Reference.
You might want to set a delay between the packets in a multiple-packet update if there are some slower PCs on the network or on slower-speed interfaces.
To adjust RIP update timers on a per-interface basis, use one or all of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx update interval {rip | sap} {value | changes-only | passive}
5. ipx output-rip-delay delay
6. ipx triggered-rip-delay delay
7. end
DETAILED STEPS
To adjust RIP update timers on a global basis, use one or both of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx default-output-rip-delay delay
4. ipx default-triggered-rip-delay delay
5. end
DETAILED STEPS
By default, the RIP entry for a network or server ages out at an interval equal to three times the RIP timer. To configure the multiplier that controls the interval, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx rip-multiplier multiplier
5. end
DETAILED STEPS
Configuring RIP Update Packet Size
By default, the maximum size of RIP updates sent out an interface is 432 bytes. This size allows for 50 routes at 8 bytes each, plus a 32-byte IPX RIP header. To modify the maximum packet size, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx rip-max-packetsize bytes
5. end
DETAILED STEPS
Configuring Static SAP Table Entries
Servers use SAP to advertise their services via broadcast packets. The Cisco IOS software stores this information in the SAP table, also known as the Server Information Table. This table is updated dynamically. You might want to explicitly add an entry to the Server Information Table so that clients always use the services of a particular server. Static SAP assignments always override any identical entries in the SAP table that are learned dynamically, regardless of hop count. If a dynamic route that is associated with a static SAP entry is lost or deleted, the software will not announce the static SAP entry until it relearns the route.
To add a static entry to the SAP table, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx sap service-type name network.node socket hop-count
4. end
DETAILED STEPS
Configuring the Queue Length for SAP Requests
The Cisco IOS software maintains a list of SAP requests to process, including all pending Get Nearest Server (GNS) queries from clients attempting to reach servers. When the network is restarted following a power failure or other unexpected event, the router can be inundated with hundreds of requests for servers. Typically, many of these are repeated requests from the same clients. You can configure the maximum length allowed for the pending SAP requests queue. SAP requests received when the queue is full are dropped, and the client must resend them.
To set the queue length for SAP requests, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx sap-queue-maximum number
4. end
DETAILED STEPS
Adjusting SAP Update Timers
You can adjust the interval at which SAP updates are sent. You can also set the delay between packets of a multiple-packet SAP update on a per-interface or global basis. Additionally, you can specify the delay between packets of a multiple-packet triggered SAP update on a per-interface or global basis.
Changing the interval at which SAP updates are sent is most useful on limited-bandwidth, point-to-point links such as slower-speed interfaces. You should ensure that all IPX servers and routers on a given network have the same SAP interval. Otherwise, they might decide that a server is down when it is really up.
It is not possible to change the interval at which SAP updates are sent on most PC-based servers. Therefore, you should never change the interval for an Ethernet or Token Ring network that has servers on it.
You can set the router to send an update only when changes have occurred. Using the changes-only keyword specifies the sending of a SAP update only when the link comes up, when the link is downed administratively, or when the databases change. The changes-only keyword causes the router to do the following:
•Send a single, full broadcast update when the link comes up
•Send appropriate triggered updates when the link is shut down
•Send appropriate triggered updates when specific service information changes
To modify the SAP update timers on a per-interface basis, use one or all of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx update interval {rip | sap} {value | changes-only | passive}
5. ipx output-sap-delay delay
6. ipx triggered-sap-delay delay
7. end
DETAILED STEPS
To adjust SAP update timers on a global basis (eliminating the need to configure delays on a per-interface basis), use one or both of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx default-output-sap-delay delay
4. ipx default-triggered-sap-delay delay
5. end
DETAILED STEPS
By default, the SAP entry of a network or server ages out at an interval equal to three times the SAP update interval. To configure the multiplier that controls the interval, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx sap-multiplier multiplier
5. end
DETAILED STEPS
Configuring SAP Update Packet Size
By default, the maximum size of SAP updates sent out on an interface is 480 bytes. This size allows for seven servers (64 bytes each), plus a 32-byte IPX SAP header. To modify the maximum packet size, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx sap-max-packetsize bytes
5. end
DETAILED STEPS
Enabling SAP-after-RIP
The IPX SAP-after-RIP feature links SAP updates to RIP updates so that SAP broadcast and unicast updates automatically occur immediately after the completion of the corresponding RIP update. This feature ensures that a remote router does not reject service information because it lacks a valid route to the service. As a result of this feature, periodic SAP updates are sent at the same interval as RIP updates.
The default behavior of the router is to send RIP and SAP periodic updates with each using its own update interval, depending on the configuration. In addition, RIP and SAP periodic updates are jittered slightly, such that they tend to diverge from each other over time. This feature synchronizes SAP and RIP updates.
Sending all SAP and RIP information in a single update reduces bandwidth demands and eliminates erroneous rejections of SAP broadcasts.
Linking SAP and RIP updates populates the service table of the remote router more quickly, because services will not be rejected due to the lack of a route to the service. Populating the service table more quickly can be especially useful on WAN circuits where the update intervals have been greatly increased to reduce the overall level of periodic update traffic on the link.
To configure the router to send a SAP update following a RIP broadcast, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx update sap-after-rip
5. end
DETAILED STEPS
Disabling Sending of General RIP or SAP Queries
You can disable the sending of general RIP or SAP queries on a link when it first comes up to reduce traffic and save bandwidth.
RIP and SAP general queries are normally sent by remote routers when a circuit first comes up. On WAN circuits, two full updates of each kind are often sent across the link. The first update is a full broadcast update, triggered locally by the link-up event. The second update is a specific (unicast) reply triggered by the general query received from the remote router. If you disable the sending of general queries when the link first comes up, it is possible to reduce traffic to a single update, and save bandwidth.
To disable the sending of a general RIP or SAP query when an interface comes up, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx linkup-request {rip | sap}
5. end
DETAILED STEPS
To reenable the sending of a general RIP or SAP query, use the positive form of the command.
Controlling Responses to GNS Requests
You can set the method in which the router responds to SAP GNS requests, you can set the delay time in responding to these requests, or you can disable the sending of responses to these requests altogether.
By default, the router responds to GNS requests if appropriate. For example, if a local server with a better metric exists, then the router does not respond to the GNS request on that segment.
The default method of responding to GNS requests is to respond with the server whose availability was learned most recently.
To control responses to GNS requests, use one or both of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx gns-round-robin
4. ipx gns-response-delay [milliseconds]
5. end
DETAILED STEPS
Note The ipx gns-response-delay command is also supported as an interface configuration command. To override the global delay value for a specific interface, use the ipx gns-response-delay command in interface configuration mode.
To disable GNS queries on a per-interface basis, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx gns-reply-disable
5. end
DETAILED STEPS
Configuring Load Sharing
To configure IPX to perform round-robin or per-host load sharing, perform the tasks described in the following sections:
•Enabling Round-Robin Load Sharing (Optional)
•Enabling per-Host Load Sharing (Optional)
Enabling Round-Robin Load Sharing
You can set the maximum number of equal-cost, parallel paths to a destination. (Note that when paths have differing costs, the Cisco IOS software chooses lower-cost routes in preference to higher-cost routes.) The software then distributes output on a packet-by-packet basis in round-robin fashion. That is, the first packet is sent along the first path, the second packet along the second path, and so on. When the final path is reached, the next packet is sent to the first path, the next to the second path, and so on. This round-robin scheme is used regardless of whether fast switching is enabled.
Limiting the number of equal-cost paths can save memory on routers with limited memory or very large configurations. Additionally, in networks with a large number of multiple paths and systems with limited ability to cache out-of-sequence packets, performance might suffer when traffic is split between many paths.
To set the maximum number of paths, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx maximum-paths paths
4. end
DETAILED STEPS
Enabling per-Host Load Sharing
Round-robin load sharing is the default behavior when you configure ipx maximum-paths to a value greater than 1. Round-robin load sharing works by sending data packets over successive equal cost paths without regard to individual end hosts or user sessions. Path utilization increases transmission speed, but, because packets destined for a given end host may take different paths, they might arrive out of order.
You can address the possibility of packets arriving out of order by enabling per-host load sharing. With per-host load sharing, the router still uses multiple, equal-cost paths to achieve load sharing; however, packets for a given end host are guaranteed to take the same path, even if multiple, equal-cost paths are available. Traffic for different end hosts tend to take different paths, but true load balancing is not guaranteed. The exact degree of load balancing achieved depends on the exact nature of the workload.
To enable per-host load sharing, use the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx maximum-paths paths
4. ipx per-host-load-share
5. end
DETAILED STEPS
Specifying the Use of Broadcast Messages
To specify the use of broadcast messages, perform the tasks described in the following sections:
•Using Helper Addresses to Forward Broadcast Packets (Optional)
•Enabling Fast Switching of IPX Directed Broadcast Packets (Optional)
Using Helper Addresses to Forward Broadcast Packets
Routers normally block all broadcast requests and do not forward them to other network segments, therefore preventing the degradation of performance over the entire network. However, you can enable the router to forward broadcast packets to helper addresses on other network segments.
How Helper Addresses Work
Helper addresses specify the network and node on another segment that can receive unrecognized broadcast packets. Unrecognized broadcast packets are non-RIP and non-SAP packets that are not addressed to the local network.
When the interface configured with helper addresses receives an unrecognized broadcast packet, Cisco IOS software changes the broadcast packet to a unicast and sends the packet to the specified network and node on the other network segment. Unrecognized broadcast packets are not flooded everywhere in your network.
With helper addresses, there is no limit on the number of hops that the broadcast packet can make.
Fast Switching Support
Cisco IOS supports fast switching of helpered broadcast packets.
When to Use Helper Addresses
You use helper addresses when you want to forward broadcast packets (except Type 20 packets) to other network segments.
Forwarding broadcast packets to helper addresses is sometimes useful when a network segment does not have an end-host capable of servicing a particular type of broadcast request. You can specify the address of a server, network, or networks that can process the broadcast packet.
Relationship Between Helper Addresses and Type 20 Propagation
You use Type 20 packet propagation to forward Type 20 packets to other network segments. For information on forwarding Type 20 packets, see the "Controlling the Forwarding of Type 20 Packets" section earlier in this chapter.
You can use helper addresses and Type 20 propagation together in your network. Use helper addresses to forward non-Type 20 broadcast packets and use Type 20 propagation to forward Type 20 broadcast packets.
Implementation Considerations
Using helper addresses is not Novell-compliant. However, it does allow routers to forward broadcast packets to network segments that can process them without flooding the network. It also allows routers running versions of Cisco IOS that do not support Type 20 propagation to forward Type 20 packets.
The Cisco IOS software supports all-networks flooded broadcasts (sometimes referred to as all-nets flooding). These are broadcast messages that are forwarded to all networks. Use all-nets flooding carefully and only when necessary, because the receiving networks may be overwhelmed to the point that no other traffic can traverse them.
Use the ipx helper-list command, described earlier in this chapter, to define access lists that control which broadcast packets get forwarded.
Using Helper Addresses
To specify a helper address for forwarding broadcast packets, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx helper-address network.node
5. end
DETAILED STEPS
You can specify multiple helper addresses on an interface.
For an example of using helper addresses to forward broadcast messages, see the "Helper Facilities to Control Broadcast: Examples" section at the end of this chapter.
Enabling Fast Switching of IPX Directed Broadcast Packets
By default, Cisco IOS software switches packets that have been helpered to the broadcast address. To enable fast switching of these IPX-directed broadcast packets, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx broadcast-fastswitching
4. end
DETAILED STEPS
Disabling IPX Fast Switching
By default, fast switching is enabled on all interfaces that support fast switching.
Fast switching allows higher throughput by switching a packet using a cache created by previous packets. Fast switching is enabled by default on all interfaces that support fast switching.
Packet transfer performance is generally better when fast switching is enabled. However, you might want to disable fast switching in order to save memory space on interface cards and to help avoid congestion when high-bandwidth interfaces are writing large amounts of information to low-bandwidth interfaces.
Turning off fast switching increases system overhead.
To disable IPX fast switching, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx route-cache
5. end
DETAILED STEPS
Adjusting the Route Cache
Adjusting the route cache allows you to control the size of the route cache, reduce memory consumption, and improve router performance. You accomplish these tasks by controlling the route cache size and invalidation. The following sections describe these optional tasks:
•Controlling Route Cache Size (Optional)
•Controlling Route Cache Invalidation (Optional)
Controlling Route Cache Size
You can limit the number of entries stored in the IPX route cache to free up router memory and aid router processing.
Storing too many entries in the route cache can use a significant amount of router memory, causing router processing to slow. This situation is most common on large networks that run network management applications for NetWare.
For example, if a network management station is responsible for managing all clients and servers in a very large (greater than 50,000 nodes) Novell network, the routers on the local segment can become inundated with route cache entries. You can set a maximum number of route cache entries on these routers to free up router memory and aid router processing.
To set a maximum limit on the number of entries in the IPX route cache, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx route-cache max-size size
4. end
DETAILED STEPS
If the route cache has more entries than the specified limit, the extra entries are not deleted. However, they may be removed if route cache invalidation is in use. See the "Controlling Route Cache Invalidation" section later in this chapter for more information on invalidating route cache entries.
Controlling Route Cache Invalidation
You can configure the router to invalidate fast-switch cache entries that are inactive. If these entries remain invalidated for 1 minute, the router purges the entries from the route cache.
Purging invalidated entries reduces the size of the route cache, reduces memory consumption, and improves router performance. Also, purging entries helps ensure accurate route cache information.
You specify the period of time that valid fast-switch cache entries must be inactive before the router invalidates them. You can also specify the number of cache entries that the router can invalidate per minute.
To configure the router to invalidate fast-switch cache entries that are inactive, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx route-cache inactivity-timeout period [rate]
4. end
DETAILED STEPS
When you use the ipx route-cache inactivity-timeout command with the ipx route-cache max-size command, you can ensure a small route cache with fresh entries.
Adjusting Default Routes
You can adjust the use of default routes in your IPX network. You can turn off the use of network number -2 as the default route. You can also specify that the router advertise only default RIP routes out an interface. The following sections describe these optional tasks:
•Disabling Network Number -2 as the Default Route (Optional)
•Advertising Only Default RIP Routes (Optional)
Disabling Network Number -2 as the Default Route
The default route is used when a route to any destination network is unknown. All packets for which a route to the destination address is unknown are forwarded to the default route. By default, IPX treats network number -2 (0xFFFFFFFE) as the default route.
For an introduction to default routes, see the "IPX Default Routes" section earlier in this chapter. For more background information on how to handle IPX default routes, refer to the Novell NetWare Link Services Protocol (NLSP) Specification, Revision 1.1 publication.
By default, Cisco IOS software treats network -2 as the default route. You can disable this default behavior and use network -2 as a regular network number in your network.
To disable the use of network number -2 as the default route, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. no ipx default-route
4. end
DETAILED STEPS
Advertising Only Default RIP Routes
Unless configured otherwise, all known RIP routes are advertised out each interface. However, you can choose to advertise only the default RIP route if it is known, therefore greatly reducing the CPU overhead when routing tables are large.
To advertise only the default route via an interface, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx advertise-default-route-only network
5. end
DETAILED STEPS
Padding Odd-Length Packets
Some IPX end hosts accept only even-length Ethernet packets. If the length of a packet is odd, the packet must be padded with an extra byte so that end host can receive it. By default, Cisco IOS pads odd-length Ethernet packets.
However, there are cases in certain topologies where nonpadded Ethernet packets are forwarded onto a remote Ethernet network. Under specific conditions, you can enable padding on intermediate media as a temporary workaround for this problem. Note that you should perform this task only under the guidance of a customer engineer or other service representative.
To enable the padding of odd-length packets, use the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx route-cache
5. ipx pad-process-switched-packets
6. end
DETAILED STEPS
Shutting Down an IPX Network
You can administratively shut down an IPX network in two ways. In the first way, the network still exists in the configuration, but is not active. When shutting down, the network sends out update packets informing its neighbors that it is shutting down, therefore allowing the neighboring systems to update their routing, SAP, and other tables without needing to wait for routes and services learned via this network to time out.
To shut down an IPX network such that the network still exists in the configuration, use the following command in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. ipx down network
5. end
DETAILED STEPS
To shut down an IPX network and remove it from the configuration, use one of the following commands in interface configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. interface type number
4. no ipx network
5. no ipx network network (where network is 1, the primary interface)
6. no ipx network network (where network is the number of the secondary interface [not 1])
7. end
DETAILED STEPS
When multiple networks are configured on an interface and you want to shut down one of the secondary networks and remove it from the interface, use the second command in the previous table specifying the network number of one of the secondary networks.
For an example of shutting down an IPX network, see the "IPX Routing: Examples" section at the end of this chapter.
Configuring IPX Accounting
IPX accounting enables you to collect information about IPX packets and the number of bytes that are switched through the Cisco IOS software. You collect information based on the source and destination IPX address. IPX accounting tracks only IPX traffic that is routed out an interface on which IPX accounting is configured; it does not track traffic generated by or terminated at the router itself.
The Cisco IOS software maintains two accounting databases: an active database and a checkpoint database. The active database contains accounting data tracked until the database is cleared. When the active database is cleared, its contents are copied to the checkpoint database. Using these two databases together enables you to monitor both current traffic and traffic that has previously traversed the router.
Switching Support
Process and fast switching support IPX accounting statistics. Autonomous and silicon switching engine (SSE) switching do not support IPX accounting statistics.
Note CiscoBus (Cbus) and SSE are not supported on the MIP interface.
Access List Support
IPX access lists support IPX accounting statistics.
IPX Accounting Task List
To configure IPX accounting, perform the tasks in the following sections. The first task is required; the remaining task is optional.
•Enabling IPX Accounting (Required)
•Customizing IPX Accounting (Optional)
Enabling IPX Accounting
To enable IPX accounting, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx accounting-list network-host network-mask
4. end
DETAILED STEPS
Customizing IPX Accounting
To customize IPX accounting, use one or more of the following commands in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx accounting-threshold threshold
4. ipx accounting-transits count
5. ipx accounting-list network-host network-mask
6. end
DETAILED STEPS
Transit entries are entries in the database that do not match any of the networks specified by the ipx accounting-list commands.
If you enable IPX accounting on an interface but do not specify an accounting list, IPX accounting tracks all traffic through the interface (all transit entries) up to the accounting threshold limit.
For an example of how to configure IPX accounting, see the "IPX Accounting: Example" section at the end of this chapter.
Configuring IPX Between LANs
Cisco IOS software supports routing IPX between Ethernet-emulated LANs and Token Ring-emulated LANs. For more information on emulated LANs and routing IPX between them, refer to the "Configuring LAN Emulation" chapter of the Cisco IOS Switching Services Configuration Guide.
Configuring IPX Between VLANs
Cisco IOS software supports routing IPX between VLANs. Users with Novell NetWare environments can configure any one of the four IPX Ethernet encapsulations to be routed using the Inter-Switch Link (ISL) encapsulation across VLAN boundaries. For more information on VLANs and routing IPX between them over ISL, refer to the "Configuring Routing Between VLANs with ISL Encapsulation" chapter of the Cisco IOS Switching Services Configuration Guide.
Configuring IPX Multilayer Switching
Cisco IOS software supports IPX Multilayer Switching (MLS). For more information on IPX MLS, refer to the "Multilayer Switching" chapter of the Cisco IOS Switching Services Configuration Guide.
Monitoring and Maintaining the IPX Newtork
To monitor and maintain your IPX network, perform the optional tasks described in the following sections:
•General Monitoring and Maintaining Tasks (Optional)
•Monitoring and Maintaining IPX Enhanced IGRP (Optional)
•Monitoring and Maintaining IPX Accounting (Optional)
General Monitoring and Maintaining Tasks
You can perform one or more of these general monitoring and maintaining tasks as described in the following sections:
•Monitoring and Maintaining Caches, Tables, Interfaces, and Statistics (Optional)
•Specifying the Type and Use of Ping Packets (Optional)
•Troubleshooting Network Connectivity (Optional)
Monitoring and Maintaining Caches, Tables, Interfaces, and Statistics
To monitor and maintain caches, tables, interfaces, or statistics in a Novell IPX network, use one or more of the following commands in EXEC mode:
Specifying the Type and Use of Ping Packets
The Cisco IOS software can send Cisco pings and standard Novell pings as defined in the NLSP specification or diagnostic request packets. By default, the software generates Cisco pings. To choose the ping type, use the following command in global configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx ping-default {cisco | novell | diagnostic}
4. end
DETAILED STEPS
The IPX diagnostic ping feature addresses diagnostic related issues by accepting and processing unicast or broadcast diagnostic packets. It makes enhancements to the current IPX ping command to ping other stations using the diagnostic packets and display the configuration information in the response packet.
Note When a ping is sent from one station to another, the response is expected to come back immediately; when the ipx ping-default command is set to diagnostics, the response could consist of more than one packet and each node is expected to respond within 0.5 seconds of receipt of the request. Due to the absence of an end-of-message flag, there is a delay and the requester must wait for all responses to arrive. Therefore, in verbose mode there may be a brief delay of 0.5 seconds before the response data is displayed.
The ipx ping command using the diagnostic keyword can be used to conduct a reachability test and should not be used to measure accurate round-trip delay.
To initiate a ping, use one of the following commands in EXEC mode:
Troubleshooting Network Connectivity
To trace the IPX destination and measure roundtrip delays, use the following command in either user or privileged EXEC mode:
|
|
|
|
|---|---|---|
Step 1 |
Router> trace [protocol] [destination] |
Traces packet routes through the network (user or privileged). |
Note In user EXEC mode, you are not allowed to change the trace route timeout interval, probe count, minimum and maximum time to live, and verbose mode. To do so, use the trace command in privileged EXEC mode.
Monitoring and Maintaining IPX Enhanced IGRP
To monitor and maintain Enhanced IGRP on an IPX network, use one or more of the following commands in EXEC mode:
Logging Enhanced IGRP Neighbor Adjacency Changes
You can enable the logging of neighbor adjacency changes to monitor the stability of the routing system and to help you detect problems. By default, adjacency changes are not logged.
To enable logging of Enhanced IGRP neighbor adjacency changes, use the following command in IPX-router configuration mode:
SUMMARY STEPS
1. enable
2. configure terminal
3. ipx router {eigrp | rip} autonomous-system-number
4. log-neighbor-changes
5. end
DETAILED STEPS
Monitoring and Maintaining IPX Accounting
To monitor and maintain IPX accounting in your IPX network, use the following commands in EXEC mode:
Configuration Examples for Novell IPX
This section provides the following IPX configuration examples:
•Helper Facilities to Control Broadcast: Examples
IPX Routing: Examples
This section shows examples for enabling IPX routing on interfaces with a single network and with multiple networks. It also shows how to enable and disable various combinations of routing protocols.
The following sections provide these examples:
•IPX Routing on a Single Network: Example
•IPX Routing on Multiple Networks: Examples
•IPX Routing Protocols: Examples
IPX Routing on a Single Network: Example
The following example shows how to enable IPX routing, defaulting the IPX host address to that of the first IEEE-conformance interface (in this example, Ethernet 0). Routing is then enabled on Ethernet 0 and Ethernet 1 for IPX networks 2abc and 1def, respectively.
ipx routing
interface ethernet 0
ipx network 2abc
interface ethernet 1
ipx network 1def
IPX Routing on Multiple Networks: Examples
There are two ways to enable IPX on an interface that supports multiple networks. You can use subinterfaces or primary and secondary networks. This section gives an example of each.
Subinterfaces Example
The following example shows how to use subinterfaces to create four logical networks on ethernet interface 0. Each subinterface has a different encapsulation. Any interface configuration parameters that you specify on an individual subinterface are applied to that subinterface only.
ipx routing
interface ethernet 0.1
ipx network 1 encapsulation novell-ether
interface ethernet 0.2
ipx network 2 encapsulation snap
interface ethernet 0.3
ipx network 3 encapsulation arpa
interface ethernet 0.4
ipx network 4 encapsulation sap
Note When enabling NLSP and configuring multiple encapsulations on the same physical LAN interface, you must use subinterfaces. You cannot use secondary networks.
You can administratively shut down each of the four subinterfaces separately by using the shutdown interface configuration command for each subinterface. The following example shows how to administratively shut down a subinterface:
interface ethernet 0.3
shutdown
To bring down network 1, use the following commands:
interface ethernet 0.1
ipx down 1
To bring network 1 back up, use the following commands:
interface ethernet 0.1
no ipx down 1
To remove all the networks on the interface, use the following interface configuration commands:
interface ethernet 0.1
no ipx network
interface ethernet 0.2
no ipx network
interface ethernet 0.3
no ipx network
interface ethernet 0.4
no ipx network
Primary and Secondary Networks Example
Note The following examples discuss primary and secondary networks. In future Cisco IOS software releases, primary and secondary networks will not be supported. Use subinterfaces.
The following example shows how to use primary and secondary networks to create the same four logical networks as shown earlier in this section. Any interface configuration parameters that you specify on this interface are applied to all the logical networks. For example, if you set the routing update timer to 120 seconds, this value is used on all four networks.
ipx routing
interface ethernet 0
ipx network 1 encapsulation novell-ether
ipx network 2 encapsulation snap secondary
ipx network 3 encapsulation arpa secondary
ipx network 4 encapsulation sap secondary
Using this method to configure logical networks, if you administratively shut down Ethernet interface 0 using the shutdown interface configuration command, all four logical networks are shut down. You cannot bring down each logical network independently using the shutdown command; however, you can bring them down using the ipx down command.
The following example shows how to shut down network 1:
interface ethernet 0
ipx down 1
The following example shows how to bring the network back up:
interface ethernet 0
no ipx down 1
The following two examples show how to shut down all four networks on the interface and remove all the networks on the interface:
no ipx network
no ipx network 1
The following example shows how to remove one of the secondary networks on the interface (in this case, network 2):
no ipx network 2
The following example shows how to enable IPX routing on FDDI interfaces 0.2 and 0.3. On FDDI interface 0.2, the encapsulation type is SNAP. On FDDI interface 0.3, the encapsulation type is the Novell FDDI_RAW.
ipx routing
interface fddi 0.2
ipx network f02 encapsulation snap
interface fddi 0.3
ipx network f03 encapsulation novell-fddi
IPX Routing Protocols: Examples
Three routing protocols can run over interfaces configured for IPX: RIP, Enhanced IGRP, and NLSP. This section provides examples of how to enable and disable various combinations of routing protocols.
When you enable IPX routing with the ipx routing global configuration command, the RIP routing protocol is automatically enabled. The following example shows how to enable RIP on networks 1 and 2:
ipx routing
!
interface ethernet 0
ipx network 1
!
interface ethernet 1
ipx network 2
The following example shows how to enable RIP on networks 1 and 2 and Enhanced IGRP on network 1:
ipx routing
!
interface ethernet 0
ipx network 1
!
interface ethernet 1
ipx network 2
!
ipx router eigrp 100
network 1
The following example shows how to enable RIP on network 2 and Enhanced IGRP on network 1:
ipx routing
!
interface ethernet 0
ipx network 1
!
interface ethernet 1
ipx network 2
!
ipx router eigrp 100
ipx network 1
!
ipx router rip
no ipx network 1
The following example shows how to configure NLSP on two Ethernet interfaces of the router. Note that RIP is automatically enabled on both of these interfaces. This example assumes that the encapsulation type is Ethernet 802.2.
ipx routing
ipx internal-network 3
!
ipx router nlsp area1
area-address 0 0
!
interface ethernet 0
ipx network e0 encapsulation sap
ipx nlsp area1 enable
!
interface ethernet 1
ipx network e1 encapsulation sap
ipx nlsp area1 enable
Enhanced IGRP: Examples
The following sections show several examples of how to configure IPX Enhanced IGRP routing:
•IPX SAP-Incremental IGRP Example
•Enhanced IGRP SAP Update Examples
•Advertisement and Processing of SAP Update Examples
•IPX Enhanced IGRP Bandwidth Configuration Example
IPX Enhanced IGRP Example
The following example shows how to configure two interfaces for Enhanced IGRP routing in autonomous system 1:
ipx routing
!
interface ethernet 0
ipx network 10
!
interface serial 0
ipx network 20
!
ipx router eigrp 1
network 10
network 20
IPX SAP-Incremental IGRP Example
The following example shows a sample configuration for enabling the IPX SAP Enhanced IGRP:
ipx routing
!
interface ethernet 0
ipx network 1
ipx sap-incremental eigrp 1
ipx sap-incremental split-horizon
!
ipx router eigrp 100
network 1
Enhanced IGRP SAP Update Examples
If an Ethernet interface has neighbors that are all configured for Enhanced IGRP, you might want to reduce the bandwidth used by SAP packets by sending SAP updates incrementally. The following example shows how to send SAP updates incrementally:
ipx routing
!
interface ethernet 0
ipx network 10
ipx sap-incremental eigrp 1
!
interface serial 0
ipx network 20
!
ipx router eigrp 1
network 10
network 20
The following example shows how to send only incremental SAP updates on a serial line that is configured for Enhanced IGRP:
ipx routing
!
interface ethernet 0
ipx network 10
!
interface serial 0
ipx network 20
ipx sap-incremental eigrp 1 rsup-only
!
ipx router eigrp 1
network 10
network 20
Advertisement and Processing of SAP Update Examples
The following example shows how to cause only services from network 3 to be advertised by an Enhanced IGRP routing process:
access-list 1010 permit 3
access-list 1010 deny -1
!
ipx router eigrp 100
network 3
distribute-sap-list 1010 out
IPX Enhanced IGRP Bandwidth Configuration Example
The following example shows how to configure the bandwidth used by IPX Enhanced IGRP. In this example, Enhanced IGRP process 109 is configured to use a maximum of 25 percent (or 32-kbps) of a 128-kbps circuit:
interface serial 0
bandwidth 128
ipx bandwidth-percent eigrp 109 25
The following example shows how to configure the bandwidth of a 56-kbps circuit to 20 kbps for routing policy reasons. The Enhanced IGRP process 109 is configured to use a maximum of 200 percent (or 40 kbps) of the circuit.
interface serial 1
bandwidth 20
ipx bandwidth-percent eigrp 109 200
IPX over WAN: Examples
The following sections show examples of how to configure IPX over WAN and dial interfaces.
•IPX over a WAN Interface Example
IPX over a WAN Interface Example
When you configure the Cisco IOS software to transport IPX packets over a serial interface that is running a WAN protocol such as X.25 or PPP, you specify how the packet will be encapsulated for transport. This encapsulation is not the same as the encapsulation used on an IPX LAN interface. Figure 1 illustrates IPX over a WAN interface.
Figure 1 IPX over a WAN Interface
The following example shows how to configure a serial interface for X.25 encapsulation and for several IPX subinterfaces used in a nonmeshed topology:
Configuration for Main Router
hostname Main
!
no ip routing
ipx routing 0000.0c17.d726
!
interface ethernet 0
no ip address
Novell network 100
media-type 10BaseT
!
interface serial 0
no ip address
shutdown
!
interface serial 1
no ip address
encapsulation x25
x25 address 33333
x25 htc 28
!
interface serial 1.1 point-to-point
no ip address
novell network 2
x25 map novell 2.0000.0c03.a4ad 11111 BROADCAST
!
interface serial 1.2 point-to-point
no ip address
novell network 3
x25 map novell 3.0000.0c07.5e26 55555 BROADCAST
Configuration for Router 1
hostname Remote1
!
no ip routing
ipx routing 0000.0c03.a4ad
!
interface ethernet 0
no ip address
novell network 1
!
interface serial 0
no ip address
encapsulation x25
novell network 2
x25 address 11111
x25 htc 28
x25 map novell 2.0000.0c17.d726 33333 BROADCAST
Configuration for Router 2
hostname Remote2
!
no ip routing
ipx routing 0000.0c07.5e26
!
interface ethernet 0
no ip address
novell network 4
media-type 10BaseT
!
interface serial 0
no ip address
shutdown
!
interface serial 1
no ip address
encapsulation x25
novell network 3
x25 address 55555
x25 htc 28
x25 map novell 3.0000.0c17.d726 33333 BROADCAST
IPX over DDR Example
In the configuration shown in Figure 2, an IPX client is separated from its server by a DDR telephone line.
Figure 2 IPX over DDR Configuration
Routing and service information is sent every 60 seconds. The output RIP and SAP filters defined in this example filter these updates, preventing them from being sent between Router A and Router B. If you forwarded these packets, each of the two routers would need to telephone the other once every 60 seconds. On a serial link whose charges are based on the number of packets sent, this activity is generally not desirable. (This problem may not occur on a dedicated serial line.)
Once the server and client have established contact, the server will send watchdog keepalive packets regularly. When SPX is used, both the server and the client send keepalive packets whose purpose is to ensure that the connection between the server and the client is still functional; these packets contain no other information. Servers send watchdog packets approximately every 5 minutes.
If Router A were allowed to forward the keepalive packets of the server to Router B, Router A would need to telephone Router B every 5 minutes just to send these packets. Again, on a serial link whose charges are based on the number of packets sent, this activity is generally not desirable. Instead of having Router A telephone Router B only to send keepalive packets, you can enable watchdog spoofing on Router A. The result will be that when the server connected to this router sends keepalive packets, Router A will respond on behalf of the remote client (the client connected to Router B). When SPX is used, enable spoofing of SPX keepalive packets on both routers A and B to inhibit the sending of them because both the server and the client send keepalive packets.
Use the ipx watchdog-spoof interface configuration command to enable and set the duration of watchdog spoofing. You can specify the number of consecutive hours spoofing is to stay enabled and the number of minutes spoofing is to stay disabled. Use this command only on a serial interface whose fast switching and autonomous switching are disabled.
The following example shows how to configure Router A. Watchdog spoofing will be enabled for 1 hour and disabled for 20 minutes, allowing the server to clean up inactive connections before being enabled again.
ipx routing 0000.0c04.4878
!
interface Ethernet0
ipx network 15200
!
interface Serial0 ! PPP encap for DDR(recommended)
encapsulation ppp
ipx network DD1DD2
! Kill all rip updates
ipx output-network-filter 801
! Kill all sap updates
ipx output-sap-filter 1001
! fast-switching off for watchdog spoofing
no ipx route-cache
! Don't listen to rip
ipx router-filter 866
! IPX watchdog spoofing
ipx watchdog-spoof 1 20
!SPX watchdog spoofing
ipx spx-spoof
! Turn on DDR
dialer in-band
dialer idle-timeout 200
dialer map IP 198.92.96.132 name R13 7917
dialer map IPX DD1DD2.0000.0c03.e3c3 7917
dialer-group 1
ppp authentication chap
! Chap authentication required
pulse-time 1
!
access-list 801 deny FFFFFFFF
access-list 866 deny FFFFFFFF
! Serialization packets
access-list 900 deny 0 FFFFFFFF 0 FFFFFFFF 457
! RIP packets
access-list 900 deny 1 FFFFFFFF 453 FFFFFFFF 453
! SAP packets
access-list 900 deny 4 FFFFFFFF 452 FFFFFFFF 452
! Permit everything else
access-list 900 permit -1 FFFFFFFF 0 FFFFFFFF 0
!
access-list 1001 deny FFFFFFFF
!
! Static ipx route for remote network
ipx route DD1 DD1DD2.0000.0c03.e3c3
!
!
! IPX will trigger the line up (9.21 and later)
dialer-list 1 list 900
IPX Network Access: Examples
The following sections show examples of how to control access to your IPX network. The sections show the configurations for various access lists and filters.
•Standard Named Access List Example
•Extended Named Access List Time Range Example
•GGS SAP Response Filter Example
IPX Network Access Example
Using access lists to manage traffic routing is a powerful tool in overall network control. However, it requires a certain amount of planning and the appropriate application of several related commands. Figure 3 illustrates a network featuring two routers on two network segments.
Figure 3 Novell IPX Servers Requiring Access Control
Suppose you want to prevent clients and servers on Network aa from using the services on Network bb, but you want to allow the clients and servers on Network bb to use the services on Network aa. To achieve this configuration, you would need an access list on Ethernet interface 1 on Router 2 that blocks all packets coming from Network aa and destined for Network bb. You would not need any access list on Ethernet interface 0 on Router 1.
The following example shows how to configure Ethernet interface 1 on Router 2:
ipx routing
access-list 800 deny aa bb01
access-list 800 permit -1 -1
interface ethernet 1
ipx network bb
ipx access-group 800
The following example shows how you can accomplish the same result as the previous example more efficiently by placing an input filter on interface Ethernet 0 of Router 1. You can also place the same output filter on Router 1, interface serial 0.
ipx routing
access-list 800 deny aa bb01
access-list 800 permit -1 -1
interface ethernet 0
ipx network aa
ipx access-group 800 in
Note When using access control list logging on an interface with fast switching turned on, packets that match the access list (and thus need to be logged) are slow switched, not fast switched.
Logging Access Control List Violations
The following example shows how you can keep a log of all access control list violations by using the keyword log at the end of the access-list command:
access-list 907 deny -1 -1 0 100 0 log
The previous example denies and logs all packets that arrive at the router from any source in any protocol from any socket to any destination on network 100.
The following example shows a log entry for the access-list command:
%IPX-6-ACL: 907 deny SPX B5A8 50.0000.0000.0001 B5A8 100.0000.0000.0001 10 pkts
In this example, ten SPX packets were denied because they matched access list number 907. The packets were coming from socket B5A8 on networks 50.0000.0000.0001 and were destined for socket B5A8 on network 100.0000.0000.0001.
Standard Named Access List Example
The following example shows how to create a standard access list named fred. It denies communication with only IPX network number 5678.
ipx access-list standard fred
deny 5678 any
permit any
Extended Named Access List Time Range Example
The following example shows how to create an extended access list named test. It permits SPX traffic only on Monday through Friday between the hours of 8:00 a.m. and 6:00 p.m.
time-range no-spx
periodic weekdays 8:00 to 18:00
!
ipx access-list extended test
permit spx any all any all time-range no spx
SAP Input Filter Example
SAP input filters allow a router to determine whether to accept information about a service.
Router C1, illustrated in Figure 4, will not accept and, consequently not advertise, any information about Novell server F. However, Router C1 will accept information about all other servers on the network 3c. Router C2 receives information about servers D and B.
Figure 4 SAP Input Filters
The following example shows how to configure Router C1. The first line denies server F, and the second line accepts all other servers.
access-list 1000 deny 3c01.0000.0000.0001
access-list 1000 permit -1
interface ethernet 0
ipx network 3c
ipx input-sap-filter 1000
interface ethernet 1
ipx network 4d
interface serial 0
ipx network 2b
Note NetWare versions 3.11 and later use an internal network and node number as their address for access list commands (the first configuration command in this example).
SAP Output Filter Example
SAP output filters are applied prior to the Cisco IOS software sending information out a specific interface. In the example that follows, Router C1 (illustrated in Figure 5) is prevented from advertising information about Novell server A out interface Ethernet 1, but can advertise server A on network 3c.
Figure 5 SAP Output Filters
The following example shows how to configure Router C1. The first line denies server A. All other servers are permitted.
access-list 1000 deny aa01.0000.0000.0001
access-list 1000 permit -1
interface ethernet 0
novell net 3c
interface ethernet 1
ipx network 4d
ipx output-sap-filter 1000
interface serial 0
ipx network 2b
GGS SAP Response Filter Example
GGS SAP response filters as shown in Figure 6 allow a router to determine whether to forward information it receives about a service.
Figure 6 GGS SAP Response Filter
The following example shows how to configure GGS SAP response filters for Router C. When the client issues a GGS request, the output GGS filter denies a response from Novell Server A and permits responses from Novell servers B and C.
access-list 1000 deny 3c01.0000.0000.0001
access-list 1000 permit -1
interface ethernet 0
ipx network 3c
interface ethernet 1
ipx output-ggs-filter 1000
ipx network 10
IPX NetBIOS Filter Examples
The following example shows how to use a NetBIOS host name to filter IPX NetBIOS frames. The example denies all outgoing IPX NetBIOS frames with a NetBIOS host name of Boston on Ethernet interface 0.
netbios access-list host token deny Boston
netbios access-list host token permit *
!
ipx routing 0000.0c17.d45d
!
interface ethernet 0
ipx network 155 encapsulation ARPA
ipx output-rip-delay 60
ipx triggered-rip-delay 30
ipx output-sap-delay 60
ipx triggered-sap-delay 30
ipx type-20-propagation
ipx netbios output-access-filter host token
no mop enabled
!
interface ethernet 1
no ip address
ipx network 105
!
interface fddi 0
no ip address
no keepalive
ipx network 305 encapsulation SAP
!
interface serial 0
no ip address
shutdown
!
interface serial 1
no ip address
no keepalive
ipx network 600
ipx output-rip-delay 100
ipx triggered-rip-delay 60
ipx output-sap-delay 100
ipx triggered-sap-delay 60
ipx type-20-propagation
The following example shows how to use a byte pattern to filter IPX NetBIOS frames. This example permits IPX NetBIOS frames from IPX network numbers that end in 05, which means that all IPX NetBIOS frames from Ethernet interface 1 (network 105) and FDDI interface 0 (network 305) will be forwarded by serial interface 0. However, this interface will filter out and not forward all frames from Ethernet interface 0 (network 155).
netbios access-list bytes finigan permit 2 **05
!
ipx routing 0000.0c17.d45d
!
ipx default-output-rip-delay 1000
ipx default-triggered-rip-delay 100
ipx default-output-sap-delay 1000
ipx default-triggered-sap-delay 100
!
interface ethernet 0
ipx network 155 encapsulation ARPA
ipx output-rip-delay 55
ipx triggered-rip-delay 55
ipx output-sap-delay 55
ipx triggered-sap-delay 55
ipx type-20-propagation
media-type 10BaseT
!
interface ethernet 1
no ip address
ipx network 105
ipx output-rip-delay 55
ipx triggered-rip-delay 55
ipx output-sap-delay 55
ipx triggered-sap-delay 55
media-type 10BaseT
!
interface fddi 0
no ip address
no keepalive
ipx network 305 encapsulation SAP
ipx output-sap-delay 55
ipx triggered-sap-delay 55
!
interface serial 0
no ip address
shutdown
!
interface serial 1
no ip address
no keepalive
ipx network 600
ipx type-20-propagation
ipx netbios input-access-filter bytes finigan
Helper Facilities to Control Broadcast: Examples
The following sections show examples of how to control broadcast messages on IPX networks:
•Forwarding to an Address Example
•Forwarding to All Networks Example
•All-Nets Flooded Broadcast Example
Note that in the following examples, packet Type 2 is used. This type has been chosen arbitrarily; the actual type to use depends on the specific application.
Forwarding to an Address Example
All broadcast packets are normally blocked by the Cisco IOS software. However, Type 20 propagation packets may be forwarded, subject to certain loop-prevention checks. Other broadcasts may be directed to a set of networks or a specific host (node) on a segment. The following examples illustrate these options.
Figure 7 shows a router (C1) connected to several Ethernet interfaces. In this environment, all IPX clients are attached to segment aa, while all servers are attached to segments bb and dd. In controlling broadcasts, the following conditions are to be applied:
•Only Type 2 and Type 20 broadcasts are to be forwarded.
•The IPX clients on network aa are allowed to broadcast via Type 2 to any server on networks bb and dd.
•The IPX clients are allowed to broadcast via Type 20 to any server on network dd.
Figure 7 IPX Clients Requiring Server Access Through a Router
The following example shows how to configure the router shown in Figure 7. The first line permits broadcast traffic of Type 2 from network aa. The interface and network commands configure each specific interface. The ipx helper-address interface configuration commands permit broadcast forwarding from network aa to bb and from network aa to dd. The helper list allows Type 2 broadcasts to be forwarded. (Note that Type 2 broadcasts are chosen as an example only. The actual type to use depends on the specific application.) The ipx type-20-propagation interface configuration command is also required to allow Type 20 broadcasts. The IPX helper-list filter is applied to both the Type 2 packets forwarded by the helper-address mechanism and the Type 20 packets forwarded by Type 20 propagation.
access-list 900 permit 2 aa
interface ethernet 0
ipx network aa
ipx type-20-propagation
ipx helper-address bb.ffff.ffff.ffff
ipx helper-address dd.ffff.ffff.ffff
ipx helper-list 900
interface ethernet 1
ipx network bb
interface ethernet 3
ipx network dd
ipx type-20-propagation
This configuration means that any network that is downstream from network aa (for example, some arbitrary network aa1) will not be able to broadcast (Type 2) to network bb through Router C1 unless the routers partitioning networks aa and aa1 are configured to forward these broadcasts with a series of configuration entries analogous to the example provided for Figure 7. These entries must be applied to the input interface and be set to forward broadcasts between directly connected networks. In this way, such traffic can be passed along in a directed manner from network to network. A similar situation exists for Type 20 packets.
The following example shows how to rewrite the ipx helper-address interface configuration command line to direct broadcasts to server A:
ipx helper-address bb.00b4.23cd.110a
! Permits node-specific broadcast forwarding to
! Server A at address 00b4.23cd.110a on network bb.
Forwarding to All Networks Example
In some networks, it might be necessary to allow client nodes to broadcast to servers on multiple networks. If you configure your router to forward broadcasts to all attached networks, you are flooding the interfaces. In the environment illustrated in Figure 8, client nodes on network 2b1 must obtain services from IPX servers on networks 3c2, 4a1, and 5bb through Router C1. To support this requirement, use the flooding address (-1.ffff.ffff.ffff) in your ipx helper-address interface configuration command specifications.
Figure 8 Type 2 Broadcasting Flooding
The first line in the following example shows how to permit traffic of Type 2 from network 2b1. Then the first interface is configured with a network number. The all-nets helper address is defined and the helper list limits forwarding to Type 2 traffic. Type 2 broadcasts from network 2b1 are forwarded to all directly connected networks. All other broadcasts, including Type 20, are blocked. To permit broadcasts, delete the ipx helper-list entry. To allow Type 20 broadcast, enable the ipx type-20-propagation interface configuration command on all interfaces.
access-list 901 permit 2 2b1
interface ethernet 0
ipx network 2b1
ipx helper-address -1.ffff.ffff.ffff
ipx helper-list 901
interface ethernet 1
ipx network 3c2
interface ethernet 2
ipx network 4a1
interface ethernet 3
ipx network 5bb
All-Nets Flooded Broadcast Example
The following example shows how to configure all-nets flooding on an interface. As a result of this configuration, Ethernet interface 0 will forward all broadcast messages (except Type 20) to all the networks it knows how to reach. This flooding of broadcast messages might overwhelm these networks with so much broadcast traffic that no other traffic may be able to pass on them.
interface ethernet 0
ipx network 23
ipx helper-address -1.FFFF.FFFF.FFFF
IPX Accounting: Example
The following example shows how to configure two Ethernet network segments that are connected via a serial link (see Figure 9). On Router A, IPX accounting is enabled on both the input and output interfaces (that is, on Ethernet interface 0 and serial interface 0), which means that statistics are gathered for traffic traveling in both directions (that is, out to the Ethernet network and out the serial link).
On Router B, IPX accounting is enabled only on the serial interface and not on the Ethernet interface, which means that statistics are gathered only for traffic that passes out the router on the serial link. Also, the accounting threshold is set to 1000, which means that IPX accounting will track all IPX traffic passing through the router up to 1000 source and destination pairs.
Figure 9 IPX Accounting Example
Configuration for Router A
ipx routing
interface ethernet 0
no ip address
ipx network C003
ipx accounting
interface serial 0
no ip address
ipx network 200
ipx accounting
Configuration for Router B
ipx routing
interface ethernet 1
no ip address
no keepalive
ipx network C001
no mop enabled
interface serial 1
no ip address
ipx network 200
ipx accounting
ipx accounting-threshold 1000
Additional References
The following sections provide references related to the Novell IPX feature.
Related Documents
Technical Assistance
Feature Information for Configuring Novell IPX
Table 3 lists the features in this module and provides links to specific configuration information.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 3 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
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Configuring Novell IPX |
12.4(11)T 15.0(1)M 12.2(33)SRE |
Novell Internetwork Packet Exchange (IPX) is derived from the Xerox Network Systems (XNS) Internet Datagram Protocol (IDP). The Cisco implementation of the Novell IPX protocol is certified to provide full IPX routing functionality. This feature was integrated into Cisco IOS This feature was integrated into Cisco IOS Release 12.2(33)SRE. The following sections provide information about this feature: • • • • • • • The following commands were modified: show ipx eigrp neighbors, show ipx eigrp topology. |
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