ASDM Book 1: Cisco ASA Series General Operations ASDM Configuration Guide, 7.2

Using Clustering

For information about using clustering with EIGRP, see Dynamic Routing and Clustering.

Enabling EIGRP

You can only enable one EIGRP routing process on the ASA.

To enable EIGRP,perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

The three tabs on the main EIGRP Setup pane used to enable EIGRP are as follows:

• The Process Instances tab lets you enable an EIGRP routing process for each context. Single context mode and multiple context mode are both supported. See Enabling EIGRP and the Enabling EIGRP Stub Routing for more information.
• The Networks tab lets you specify the networks used by the EIGRP routing process. For an interface to participate in EIGRP routing, it must fall within the range of addresses defined by the network entries. For directly connected and static networks to be advertised, they must also fall within the range of the network entries. See Defining a Network for an EIGRP Routing Process for more information.
• The Passive Interfaces tablets you configure one or more interfaces as passive interfaces. In EIGRP, a passive interface does not send or receive routing updates.The Passive Interface table lists each interface that is configured as a passive interface.

Step 2 Check the Enable this EIGRP process check box.

You can only enable one EIGRP routing process on the device. You must enter an autonomous system number (AS) for the routing process in the EIGRP Process field before you can save your changes.

Step 3 In the EIGRP Process field, enter the autonomous system (AS) number for the EIGRP process. The AS number can be from 1 to 65535.

Step 4 (Optional) Click Advanced to configure the EIGRP process settings, such as the router ID, default metrics, stub routing, neighbor changes, and the administrative distances for the EIGRP routes.

Step 5 Click the Networks tab.

Step 6 To add a new network entry, click Add.

The Add EIGRP Network dialog box appears. To remove a network entry, choose an entry in the table and click Delete.

Step 7 Choose the AS number of the EIGRP routing process from the drop-down list.

Step 8 Enter the IP address of the networks to participate in the EIGRP routing process in the IP Address field.

Note To change a network entry, you must first remove the entry and then add a new one. You cannot edit existing entries.

Step 9 Enter a network mask to apply to the IP address in the Network Mask field.

Step 10 Click OK.

Enabling EIGRP Stub Routing

You can enable, and configure the ASA as an EIGRP stub router. Stub routing decreases memory and processing requirements on the ASA. As a stub router, the ASA does not need to maintain a complete EIGRP routing table because it forwards all nonlocal traffic to a distribution router. Generally, the distribution router need not send anything more than a default route to the stub router.

Only specified routes are propagated from the stub router to the distribution router. As a stub router, the ASA responds to all queries for summaries, connected routes, redistributed static routes, external routes, and internal routes with the message “inaccessible.” When the ASA is configured as a stub, it sends a special peer information packet to all neighboring routers to report its status as a stub router. Any neighbor that receives a packet informing it of the stub status will not query the stub router for any routes, and a router that has a stub peer will not query that peer. The stub router depends on the distribution router to send the correct updates to all peers.

To enable the ASA as an EIGRP stub routing process, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the autonomous system (AS) number for the EIGRP process. The AS number can be from 1 to 65535.

Step 4 Click Advanced to configure the EIGRP stub routing process.

The Edit EIGRP Process Advanced Properties dialog box appears.

Step 5 In the Stub area on the Edit EIGRP Process Advanced Properties dialog box, choose one or more of the following EIGRP stub routing processes:

• Stub Receive only—Configures the EIGRP stub routing process to receive route information from the neighbor routers but does not send route information to the neighbors. If this option is selected, you cannot select any of the other stub routing options.
• Stub Connected—Advertises connected routes.
• Stub Static—Advertises static routes.
• Stub Redistributed—Advertises redistributed routes.
• Stub Summary—Advertises summary routes.

Step 6 Click OK.

Step 7 Click the Networks tab.

Step 8 Click Add to add a new network entry.

The Add EIGRP Network dialog box appears. To remove a network entry, choose the entry in the table and click Delete.

Step 9 Choose the AS number of the EIGRP routing process from the drop-down list.

Step 10 Enter the IP address of the networks to participate in the EIGRP routing process in the IP Address field.

Note To change a network entry, you must first remove the entry and then add a new one. You cannot edit existing entries.

Step 11 Enter a network mask to apply to the IP address in the Network Mask field.

Step 12 Click OK.

Defining a Network for an EIGRP Routing Process

The Network table lets you specify the networks used by the EIGRP routing process. For an interface to participate in EIGRP routing, it must fall within the range of addresses defined by the network entries. For directly connected and static networks to be advertised, they must also fall within the range of the network entries.

The Network table displays the networks configured for the EIGRP routing process. Each row of the table displays the network address and associated mask configured for the specified EIGRP routing process.

To add or define a network, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the autonomous system (AS) number for the EIGRP process. The AS number can be from 1 to 65535.

Step 4 Click the Networks tab.

Step 5 Click Add to add a new network entry.

The Add EIGRP Network dialog box appears. To remove a network entry, choose the entry in the table and click Delete.

Step 6 Choose the AS number of the EIGRP routing process from the drop-down list.

Step 7 Enter the IP address of the networks to participate in the EIGRP routing process in the IP Address field.

Note To change a network entry, you must first remove the entry and then add a new one. You cannot edit existing entries.

Step 8 Enter a network mask to apply to the IP address in the Network Mask field.

Step 9 Click OK.

Configuring Interfaces for EIGRP

If you have an interface that you do not want to have participate in EIGRP routing, but that is attached to a network that you want advertised, you can configure the ASA that includes the network to which the interface is attached, and prevent that interface from sending or receiving EIGRP updates.

To configure interfaces for EIGRP, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 Click OK.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane appears and displays the EIGRP interface configurations. The Interface Parameters table displays all of the interfaces on the ASA and lets you modify the following settings on a per-interface basis:

• Authentication key and mode.
• The EIGRP hello interval and hold time.
• The interface delay metric used in EIGRP metric calculations.
• The use of split-horizon on the interface.

Step 5 Choose an interface entry by double-clicking an interface entry, or choose the entry and click Edit.

The Edit EIGRP Interface Entry dialog box appears.

Step 6 In the EIGRP Process field, enter the AS number for the EIGRP process. The AS number can range from 1 to 65535.

Step 7 In the Hello Interval field, enter the interval between EIGRP hello packets sent on an interface.

Valid values range from 1 to 65535 seconds. The default value is 5 seconds.

Step 8 In the Hold Time field, enter the hold time, in seconds. Valid values range from 1 to 65535 seconds. The default value is 15 seconds.

Step 9 Check the Enable check box for Split Horizon.

Step 10 In the Delay field, enter the delay value. The delay time is in tens of microseconds. Valid values range from 1 to 16777215.

Step 11 Check the Enable MD5 Authentication check box to enable MD5 authentication of EIGRP process messages.

Step 12 Enter the Key or Key ID values.

• In the Key field, enter the key to authenticate EIGRP updates. The key can contain up to 16 characters.
• In the Key ID field, enter the key identification value. Valid values range from 1 to 255.

Step 13 Click OK.

Configuring Passive Interfaces

You can configure one or more interfaces as passive interfaces. In EIGRP, a passive interface does not send or receive routing updates.

To configure passive interfaces, perform the following steps:

Note In ASDM, the Passive Interface table lists each interface that is configured as a passive interface.

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 Click OK.

Step 4 Click the Passive Interfaces tab.

Step 5 Choose the interface that you want to configure from the drop-down list.

Step 6 Check the Suppress routing updates on all interfaces check box to specify all interfaces as passive. Even if an interface is not shown in the Passive Interface table, it will be configured as passive when the check box is checked.

Step 7 Click Add to add a passive interface entry.

The Add EIGRP Passive Interface dialog box appears. Choose the interface that you want to make passive and click Add. To remove a passive interface, choose the interface in the table and click Delete.

Step 8 Click OK.

Configuring the Summary Aggregate Addresses on Interfaces

You can configure a summary addresses on a per-interface basis. You need to manually define summary addresses if you want to create summary addresses that do not occur at a network number boundary or if you want to use summary addresses on an ASA with automatic route summarization disabled. If any more specific routes are in the routing table, EIGRP will advertise the summary address out the interface with a metric equal to the minimum of all more specific routes.

To create a summary address, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane shows the EIGRP interface configurations. The Interface Parameters table shows all of the interfaces on the ASA and lets you modify the settings on a per-interface basis. For more information about these settings, see Configuring Interfaces for EIGRP.

Step 2 To configure the EIGRP parameters for an interface, double-click an interface entry or select the entry and click Edit.

Step 3 Click OK.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Summary Address.

The Summary Address pane displays a table of the statically-defined EIGRP summary addresses. By default, EIGRP summarizes subnet routes to the network level. You can create statically defined EIGRP summary addresses to the subnet level from the Summary Address pane.

Step 5 Click Add to add a new EIGRP summary address, or to click Edit to edit an existing EIGRP summary address in the table.

The Add Summary Address or Edit Summary Address dialog box appears. You can also double-click an entry in the table to edit that entry.

Step 6 In the EIGRP Process field, enter the autonomous system (AS) number for the EIGRP process. The AS number can be from 1 to 65535.

Step 7 In the Interface drop-down list, choose the interface from which the summary address is advertised.

Step 8 In the IP Address field, enter the IP address of the summary route.

Step 9 In the Netmask field, choose or enter the network mask to apply to the IP address.

Step 10 Enter the administrative distance for the route in the Administrative Distance field. If left blank, the route has the default administrative distance of 5.

Step 11 Click OK.

Changing the Interface Delay Value

The interface delay value is used in EIGRP distance calculations. You can modify this value on a per-interface basis.

To change the interface delay value, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane shows the EIGRP interface configurations. The Interface Parameters table shows all of the interfaces on the ASA and lets you modify the settings on a per-interface basis. For more information about these settings, see Configuring Interfaces for EIGRP.

Step 2 Double-click an interface entry or choose the Interface entry and click Edit to configure the delay value in the EIGRP parameters for an interface.

The Edit EIGRP Interface Entry dialog box appears.

Step 3 In the Delay field, enter the delay time, which is in tens of microseconds. Valid values are from 1 to 16777215.

Step 4 Click OK.

Enabling EIGRP Authentication on an Interface

EIGRP route authentication provides MD5 authentication of routing updates from the EIGRP routing protocol. The MD5 keyed digest in each EIGRP packet prevents the introduction of unauthorized or false routing messages from unapproved sources.

EIGRP route authentication is configured on a per-interface basis. All EIGRP neighbors on interfaces configured for EIGRP message authentication must be configured with the same authentication mode and key for adjacencies to be established.

Note Before you can enable EIGRP route authentication, you must enable EIGRP.

To enable EIGRP authentication on an interface, perform the following steps:

Step 1 In the man ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the autonomous system (AS) number for the EIGRP process. The AS number can range from 1 to 65535.

Step 4 Click the Networks tab.

Step 5 Click Add to add a new network entry.

The Add EIGRP Network dialog box appears. To remove a network entry, choose the entry in the table and click Delete.

Step 6 Choose the AS number of the EIGRP routing process from the drop-down list.

Step 7 In the IP Address field, enter the IP address of the networks to participate in the EIGRP routing process.

Note To change a network entry, you must first remove the entry and then add a new one. You cannot edit existing entries.

Step 8 In the Network Mask field, choose or enter a network mask to apply to the IP address.

Step 9 Click OK.

Step 10 Choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane displays the EIGRP interface configurations. The Interface Parameters table displays all of the interfaces on the ASA and lets you modify the settings on a per-interface basis. For more information about these settings, see Configuring Interfaces for EIGRP.

Step 11 Check the Enable MD5 Authentication check box to enable MD5 authentication of EIGRP process messages. After you check this check box, provide one of the following:

• In the Key field, enter the key to authenticate EIGRP updates. The key can include up to 16 characters.
• In the Key ID field, enter the key identification value. Valid values range from 1 to 255.

Step 12 Click OK.

Defining an EIGRP Neighbor

EIGRP hello packets are sent as multicast packets. If an EIGRP neighbor is located across a non broadcast network, such as a tunnel, you must manually define that neighbor. When you manually define an EIGRP neighbor, hello packets are sent to that neighbor as unicast messages.

To manually define an EIGRP neighbor, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the AS number for the EIGRP process. The AS number can range from 1 to 65535.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Static Neighbor.

The Static Neighbor pane appears and displays the statically-defined EIGRP neighbors. An EIGRP neighbor sends EIGRP routing information to and receives EIGRP routing information from the ASA. Normally, neighbors are dynamically discovered through the neighbor discovery process. However, on point-to-point, nonbroadcast networks, you must statically define the neighbors.

Each row of the Static Neighbor table displays the EIGRP autonomous system number for the neighbor, the neighbor IP address, and the interface through which the neighbor is available.

From the Static Neighbor pane, you can add or edit a static neighbor.

Step 5 Click Add or Edit to add or edit a EIGRP static neighbor.

The Add or Edit EIGRP Neighbor Entry dialog box appears.

Step 6 Choose the EIGRP AS number from the drop-down list for the EIGRP process for which the neighbor is being configured.

Step 7 Choose the Interface Name from the Interface Name drop-down list, which is the interface through which the neighbor is available.

Step 8 Enter the IP address of the neighbor in the Neighbor IP Address field.

Step 9 Click OK.

Redistributing Routes Into EIGRP

You can redistribute routes discovered by RIP and OSPF into the EIGRP routing process. You can also redistribute static and connected routes into the EIGRP routing process. You do not need to redistribute connected routes if they fall within the range of a network statement in the EIGRP configuration.

Note For RIP only: Before you begin this procedure, you must create a route map to further define which routes from the specified routing protocol are redistributed in to the RIP routing process. See “Route Maps,” for more information about creating a route map.

To redistribute routes into the EIGRP routing process, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the AS number for the EIGRP process. The AS number can range from 1 to 65535.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Redistribution.

The Redistribution pane displays the rules for redistributing routes from other routing protocols to the EIGRP routing process. When redistributing static and connected routes to the EIGRP routing process, metrics are not required to be configured, although this is recommended. Each row of the Redistribution pane table includes a route redistribution entry.

Step 5 Click Add to add a new redistribution rule. If you are editing an existing redistribution rule, go to Step 6.

The Add EIGRP Redistribution Entry dialog box appears.

Step 6 Choose the address in the table and click Edit to edit an existing EIGRP static neighbor, You can also double-click an entry in the table to edit that entry.

The Edit EIGRP Redistribution Entry dialog box appears.

Step 7 Choose the AS number of the EIGRP routing process to which the entry applies from the drop-down list.

Step 8 In the Protocol area, click the radio button next to one of the following protocols for the routing process:

• Static to redistribute static routes to the EIGRP routing process. Static routes that fall within the scope of a network statement are automatically redistributed into EIGRP; you do not need to define a redistribution rule for them.
• Connected to redistribute connected routes into the EIGRP routing process. Connected routes that fall within the scope of a network statement are automatically redistributed into EIGRP; you do not need to define a redistribution rule for them.
• RIP to redistributes routes discovered by the RIP routing process to EIGRP.
• OSPF to redistribute routes discovered by the OSPF routing process to EIGRP.

Step 9 In the Optional Metrics area, choose one of the following metrics used for the redistributed route:

• Bandwidth, which is the EIGRP bandwidth metric in kilobits per second. Valid values range from 1 to 4294967295.
• Delay, which is the EIGRP delay metric, in 10-microsecond units. Valid values range from 0 to 4294967295.
• Reliability, which is the EIGRP reliability metric. Valid values range from 0 to 255; 255 indicates 100 percent reliability.
• Loading, which is the EIGRP effective bandwidth (loading) metric. Valid values range from 1 to 255; 255 indicates 100 percent loaded.
• MTU, which is the MTU of the path. Valid values range from 1 to 65535.

Step 10 Choose the route map from the Route Map drop-down list to define which routes are redistributed into the EIGRP routing process. For more details about how to configure a route map, see Chapter27, “Route Maps”

Step 11 In the Optional OSPF Redistribution area, click one of the following OSPF radio buttons to further specify which OSPF routes are redistributed into the EIGRP routing process:

• Match Internal to match routes internal to the specified OSPF process.
• Match External 1 to match type 1 routes external to the specified OSPF process.
• Match External 2 to match type 2 routes external to the specified OSPF process.
• Match NSSA-External 1 to match type 1 routes external to the specified OSPF NSSA.
• Match NSSA-External 2 to match type 2 routes external to the specified OSPF NSSA.

Step 12 Click OK.

Filtering Networks in EIGRP

Note Before you begin this process, you must create a standard ACL that defines the routes that you want to advertise. That is, create a standard ACL that defines the routes that you want to filter from sending or receiving updates.

To filter networks in EIGRP, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 In the EIGRP Process field, enter the AS number for the EIGRP process. The AS number can range from 1 to 65535.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Filter Rules.

The Filter Rules pane appears and displays the route filtering rules configured for the EIGRP routing process. Filter rules let you control which routes are accepted or advertised by the EIGRP routing process.

Each row of the Filter Rule table describes a filter rule for a specific interface or routing protocol. For example, a filter rule with a direction of in on the outside interface would apply filtering to any EIGRP updates received on the outside interface. A filter rule with a direction of out with OSPF 10 specified as the routing protocol would apply the filter rules to routes redistributed into the EIGRP routing process in outbound EIGRP updates.

Step 5 Click Add to add a filter rule. If you are editing an already existing filter rule, skip to Step 6.

The Add Filter Rules dialog box appears.

Step 6 To edit a filter rule, choose the filter rule in the table and click Edit.

The Edit Filter Rules dialog appears. You can also double-click a filter rule to edit the rule. To remove a filter rule, choose the filter rule in the table and click Delete.

Step 7 Choose the AS number from the drop-down list of the EIGRP routing process to which the entry applies.

Step 8 Choose the direction of the filter routes from the drop-down list.

Choose in for rules that filter routes from incoming EIGRP routing updates. Choose out to filter routes from EIGRP routing updates that are sent by the ASA.

If you choose out, the Routing process field becomes active. Choose the type of route to be filtered. You can filter routes redistributed from static, connected, RIP, and OSPF routing processes. Filters that specify a routing process filter those routes from updates sent on all interfaces.

Step 9 Enter the OSPF process ID in the ID field.

Step 10 Click the Interface radio button and choose the interface to which the filter applies.

Step 11 Click Add or Edit to define an ACL for the filter rule. Clicking Edit opens the Network Rule dialog box for the selected network rule.

The Network Rule dialog box appears.

Step 12 In the Action drop-down list, choose Permit to allow the specified network to be advertised; choose Deny to prevent the specified network from being advertised.

Step 13 In the IP Address field, type IP address of the network being permitted or denied. To permit or deny all addresses, use the IP address 0.0.0.0 with a network mask of 0.0.0.0.

Step 14 From the Netmask drop-down list, choose the network mask applied to the network IP address. You can type a network mask into this field or select one of the common masks from the list.

Step 15 Click OK.

Customizing the EIGRP Hello Interval and Hold Time

The ASA periodically sends hello packets to discover neighbors and to learn when neighbors become unreachable or inoperative. By default, hello packets are sent every 5 seconds.

The hello packet advertises the ASA hold time. The hold time indicates to EIGRP neighbors the length of time the neighbor should consider the ASA reachable. If the neighbor does not receive a hello packet within the advertised hold time, then the ASA is considered unreachable. By default, the advertised hold time is 15 seconds (three times the hello interval).

Both the hello interval and the advertised hold time are configured on a per-interface basis. We recommend setting the hold time to be at minimum three times the hello interval.

To configure the hello interval and advertised hold time, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 Click OK.

Step 4 Choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane appears and displays all of the EIGRP interface configurations.

Step 5 Double-click an interface entry or choose the entry and click Edit.

The Edit EIGRP Interface Entry dialog box appears.

Step 6 Choose the EIGRP AS number from the drop-down list, which is populated from system numbers that were set up when you enabled the EIGRP routing process.

Step 7 In the Hello Interval field, enter the interval between EIGRP hello packets sent on an interface.

Valid values range from 1 to 65535 seconds. The default value is 5 seconds.

Step 8 In the Hold Time field, specify the hold time, in seconds.

Valid values range from 1 to 65535 seconds. The default value is 15 seconds.

Step 9 Click OK.

Disabling Automatic Route Summarization

Automatic route summarization is enabled by default. The EIGRP routing process summarizes on network number boundaries. This can cause routing problems if you have noncontiguous networks.

For example, if you have a router with the networks 192.168.1.0, 192.168.2.0, and 192.168.3.0 connected to it, and those networks all participate in EIGRP, the EIGRP routing process creates the summary address 192.168.0.0 for those routes. If an additional router is added to the network with the networks 192.168.10.0 and 192.168.11.0, and those networks participate in EIGRP, they will also be summarized as 192.168.0.0. To prevent the possibility of traffic being routed to the wrong location, you should disable automatic route summarization on the routers creating the conflicting summary addresses.

To disable automatic route summarization in ASDM, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 Click the Process Instance tab.

Step 4 Click Advanced.

Step 5 In the Summary area, uncheck the Auto-Summary check box.

Note This setting is enabled by default.

Step 6 Click OK.

Configuring Default Information in EIGRP

You can control the sending and receiving of default route information in EIGRP updates. By default, default routes are sent and accepted. Configuring the ASA to disallow default information to be received causes the candidate default route bit to be blocked on received routes. Configuring the ASA to disallow default information to be sent disables the setting of the default route bit in advertised routes.

In ASDM, the Default Information pane displays a table of rules for controlling the sending and receiving of default route information in EIGRP updates. You can have one in and one out rule for each EIGRP routing process (only one process is currently supported).

By default, default routes are sent and accepted. To restrict or disable the sending and receiving of default route information, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The main EIGRP Setup pane appears.

Step 2 Check the Enable EIGRP routing check box.

Step 3 Click OK.

Step 4 Do one of the following:

• Click Add to create a new entry.
• To edit an entry, double-click the entry in the table or select an entry in the table and click Edit.

The Add Default Information or Edit Default Information dialog box appears for that entry. The EIGRP AS number is automatically selected in the EIGRP field.

Step 5 In the Direction field, choose the direction for the rule from the following options:

• in —The rule filters default route information from incoming EIGRP updates.
• out —The rule filters default route information from outgoing EIGRP updates.

You can have one in rule and one out rule for each EIGRP process.

Step 6 Add network rules to the network rule table. The network rules define which networks are allowed and which are not when receiving or sending default route information. Repeat the following steps for each network rule you are adding to the default information filter rule.

a. Click Add to add a network rule. Double-click an existing network rule to edit the rule.

b. In the Action field, click Permit to allow the network or Deny to block the network.

c. Enter the IP address and network mask of the network being permitted or denied by the rule in the IP Address and Network Mask fields.

To deny all default route information from being accepted or sent, enter 0.0.0.0 as the network address and choose 0.0.0.0 as the network mask.

d. Click OK to add the specified network rule to the default information filter rule.

Step 7 Click OK to accept the default information filter rule.

Disabling EIGRP Split Horizon

Split horizon controls the sending of EIGRP update and query packets. When split horizon is enabled on an interface, update and query packets are not sent for destinations for which this interface is the next hop. Controlling update and query packets in this manner reduces the possibility of routing loops.

By default, split horizon is enabled on all interfaces.

Split horizon blocks route information from being advertised by a router out of any interface from which that information originated. This behavior usually optimizes communications among multiple routing devices, particularly when links are broken. However, with nonbroadcast networks, there may be situations where this behavior is not desired. For these situations, including networks in which you have EIGRP configured, you may want to disable split horizon.

If you disable split horizon on an interface, you must disable it for all routers and access servers on that interface.

To disable EIGRP split horizon, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Interfaces.

The Interface pane appears and displays the EIGRP interface configurations.

Step 2 Double-click an interface entry or choose the entry and click Edit.

The Edit EIGRP Interface Entry dialog box appears.

Step 3 Choose the EIGRP Autonomous system (AS) number from the drop-down list, which is populated from system numbers that were set up when you enabled the EIGRP routing process.

Step 4 Uncheck the Split Horizon check box.

Step 5 Click OK.

Restarting the EIGRP Process

To restart an EIGRP process or clear redistribution or counters, perform the following steps:

Step 1 In the main ASDM window, choose Configuration > Device Setup > Routing > EIGRP > Setup.

The EIGRP Setup pane appears.

Step 2 Click Reset.