Contents
- Configuring Media-Independent PPP and Multilink PPP
- Finding Feature Information
- Information About Media-Independent PPP and Multilink PPP
- PPP Encapsulation Overview
- Multilink PPP
- Multilink PPP Minimum Links Mandatory
- CHAP or PAP Authentication
- Microsoft Point-to-Point Compression
- IP Address Pooling
- Peer Address Allocation
- Precedence Rules
- Interfaces Affected
- Multilink PPP Interleaving and Queueing
- How to Configure Media-Independent PPP and Multilink PPP
- Enabling PPP Encapsulation
- Enabling CHAP or PAP Authentication
- Enabling Link Quality Monitoring
- Configuring Compression of PPP Data
- Configuring MPPC
- Configuring IP Address Pooling
- Choosing the IP Address Assignment Method
- Defining the Global Default Address Pooling Mechanism
- Defining DHCP as the Global Default Mechanism
- Defining Local Address Pooling as the Global Default Mechanism
- Controlling DHCP Network Discovery
- Configuring IP Address Assignment
- Configuring PPP Reliable Link
- Troubleshooting PPP
- Disabling or Reenabling Peer Neighbor Routes
- Configuring Multilink PPP
- Configuring Multilink PPP on Synchronous Interfaces
- Creating a Multilink Bundle
- Assigning an Interface to a Multilink Bundle
- Configuring Multilink PPP Using Multilink Group Interfaces
- Configuring Multilink PPP Minimum Links Mandatory
- Changing the Default Endpoint Discriminator
- Configuring Multilink PPP Interleaving and Queueing
- Configuring Multilink PPP Interleaving
- Disabling PPP Multilink Fragmentation
- Monitoring and Maintaining PPP and Multilink PPP Interfaces
- Configuration Examples for PPP and Multilink PPP
- Example: Configuring Multilink PPP with Traffic Shaping
- Example: Enabling CHAP Authentication with an Encrypted Password
- Example: Configuring Multilink PPP on Synchronous Serial Interfaces
- Example: Configuring Multilink PPP Using Multilink Group Interfaces over ATM
- Example: Configuring Multilink PPP Interleaving and Queueing for Real-Time Traffic
- Additional References
- Feature Information for Media-Independent PPP and Multilink PPP
Configuring Media-Independent PPP and Multilink PPP
This module describes how to configure Media-Independent PPP and Multilink PPP features that can be configured on any interface.
- Finding Feature Information
- Information About Media-Independent PPP and Multilink PPP
- How to Configure Media-Independent PPP and Multilink PPP
- Configuration Examples for PPP and Multilink PPP
- Additional References
- Feature Information for Media-Independent PPP and Multilink PPP
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and 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 table at the end of this module.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Information About Media-Independent PPP and Multilink PPP
- PPP Encapsulation Overview
- Multilink PPP
- Multilink PPP Minimum Links Mandatory
- CHAP or PAP Authentication
- Microsoft Point-to-Point Compression
- IP Address Pooling
- Multilink PPP Interleaving and Queueing
PPP Encapsulation Overview
PPP, described in RFC 1661, encapsulates network layer protocol information over point-to-point links. You can configure PPP on the following types of physical interfaces:
Magic Number support is available on all serial interfaces. PPP always attempts to negotiate for Magic Numbers, which are used to detect looped-back lines. Depending on how the down-when-looped command is configured, a device might shut down a link if it detects a loop.
Multilink PPP
The Multilink PPP feature provides load balancing functionality over multiple WAN links while providing multivendor interoperability, packet fragmentation, proper sequencing, and load calculation on both inbound and outbound traffic. Cisco's implementation of Multilink PPP supports the fragmentation and packet sequencing specifications in RFC 1990. Additionally, you can change the default endpoint discriminator value that is supplied as part of user authentication. Refer to RFC 1990 for more information about the endpoint discriminator.
Multilink PPP allows packets to be fragmented and the fragments to be sent at the same time over multiple point-to-point links to the same remote address. The multiple links come up in response to a defined dialer load threshold. The load can be calculated on inbound traffic or outbound traffic, as required for the traffic between the specific sites. Multilink PPP provides bandwidth on demand and reduces transmission latency across WAN links.
Multilink PPP is designed to work over synchronous and asynchronous serial types of single or multiple interfaces that have been configured to support both dial-on-demand rotary groups and PPP encapsulation.
Multilink PPP Minimum Links Mandatory
Multilink PPP allows multiple PPP links to be established in parallel to the same destination. Multilink PPP is often used to increase the amount of bandwidth between points. The Multilink PPP Minimum Links Mandatory feature enables you to configure the minimum number of links that are required in a Multilink PPP bundle to keep the bundle active.
The Multilink PPP Minimum Links Mandatory feature causes all Network Control Protocols (NCPs) for a Multilink PPP bundle to be disabled until the Multilink PPP bundle has the required minimum number of links. When a new link is added to a Multilink PPP bundle to bring the number of links up to the required number of minimum links, the NCPs are activated for the Multilink PPP bundle. When a link is removed from a Multilink PPP bundle, the number of links falls below the required minimum number of links for that Multilink PPP bundle, and the NCPs are disabled for that Multilink PPP bundle.
CHAP or PAP Authentication
PPP with Challenge Handshake Authentication Protocol (CHAP) or Password Authentication Protocol (PAP) is often used to inform the central site about the remote devices that are connected to the site.
With this authentication information, if a device or an access server receives a packet for a destination to which the router or the access switch is already connected, an additional call is not placed. However, if the router or access server is using rotaries, the device or access server sends the packet out on the correct port.
CHAP and PAP were originally specified in RFC 1334, and CHAP is updated in RFC 1994. These protocols are supported on synchronous and asynchronous serial interfaces. When using CHAP or PAP authentication, each device or access server identifies itself using a name. This identification process prevents a device from placing another call to a device to which it is already connected and also prevents unauthorized access.
Access control using CHAP or PAP is available on all serial interfaces that use PPP encapsulation. The authentication feature reduces the risk of security violations on your device or access server. You can configure either CHAP or PAP on a serial interface.
 Note | To enable CHAP or PAP authentication on a device, the device must be running PPP encapsulation. |
When CHAP is enabled on an interface and a remote device attempts to connect to it, the local device or access server sends a CHAP packet to the remote device. The CHAP packet requests or “challenges” the remote device to respond. The challenge packet consists of an ID, a random number, and the host name of the local device.
The required response consists of the following two parts:
- An encrypted version of the ID, a secret password, and a random number
- Either the hostname of the remote device or the name of the user on the remote device
When the local device or access server receives the response, it verifies the secret password by performing the same encryption operation as indicated in the response and by looking up the required hostname or username. The secret passwords must be identical on the remote device and the local device.
Because this response is sent, the password is never sent in clear text, preventing other devices from stealing it and gaining illegal access to the system. Without a proper response, the remote device cannot connect to the local device.
CHAP transactions occur only when a link is established. The local device or access server does not request a password during the rest of the call. (The local device can, however, respond to such requests from other devices during a call.)
When PAP is enabled, the remote router attempting to connect to the local device or access server is required to send an authentication request. If the username and password specified in the authentication request are accepted, Cisco software sends an authentication acknowledgment.
After you have enabled CHAP or PAP, the local router or access server requires authentication from remote devices. If the remote device does not support the enabled protocol, no traffic is passed to that device.
Microsoft Point-to-Point Compression
Microsoft Point-to-Point Compression (MPPC) is a scheme used to compress PPP packets between Cisco and Microsoft client devices. The MPPC algorithm is designed to optimize bandwidth utilization to support multiple simultaneous connections. The MPPC algorithm uses a Lempel-Ziv (LZ)-based compression algorithm with a continuous history buffer called a dictionary.
The Compression Control Protocol (CCP) configuration option for MPPC is 18.
Exactly one MPPC datagram is encapsulated in the PPP information field. The PPP protocol field indicates the hexadecimal type of 00FD for all compressed datagrams. The maximum length of the MPPC datagram sent over PPP is the same as the maximum transmission unit (MTU) of the PPP interface; however, this length cannot be greater than 8192 bytes because the history buffer is limited to 8192 bytes. If compressing the data results in data expansion, the original data is sent as an uncompressed MPPC packet.
History buffers between the compressor and the decompressor are synchronized by maintaining a 12-bit coherency count. If the decompressor detects that the coherency count is out of sequence, the following error recovery process is performed:
- A Reset Request (RR) packet is sent from the decompressor.
- The compressor then flushes the history buffer and sets the flushed bit in the next packet it sends.
- Upon receiving the flushed bit set packet, the decompressor flushes the history buffer.
Synchronization is achieved without CCP by using the Reset Acknowledge (RA) packet, which can consume additional time.
The following steps describe how compression negotiation between a device and a Windows 95 client occurs:
- Windows 95 sends a request for both Stacker compression (STAC) (option 17) and MPPC (option 18) compression.
- The router sends a negative acknowledgment (NAK) requesting only MPPC.
- Windows 95 resends the request for MPPC.
- The device sends an acknowledgment (ACK) confirming MPPC compression negotiation.
IP Address Pooling
A point-to-point interface must be able to provide a remote node with its IP address through the IP Control Protocol (IPCP) address negotiation process. The IP address can be obtained from a variety of sources. The address can be configured through the command line, entered with an EXEC-level command, provided by TACACS+ or the Dynamic Host Configuration Protocol (DHCP), or from a locally administered pool.
IP address pooling uses a pool of IP addresses from which an incoming interface can provide an IP address to a remote node through IPCP address negotiation process. IP address pooling also enhances configuration flexibility by allowing multiple types of pooling to be active simultaneously.
For additional information about address pooling on asynchronous interfaces and Serial Line Internet Protocol (SLIP), see the “Configuring Asynchronous SLIP and PPP” module in the Dial Configuration Guide.
Peer Address Allocation
A peer IP address can be allocated to an interface using one of the following methods:
- IPCP negotiation—If the peer presents a peer IP address during IPCP address negotiation and no other peer address is assigned, the presented address is acknowledged and used in the current session.
- Default IP address—The peer default ip address command and the member peer default ip address command can be used to define default peer IP addresses.
- TACACS+-assigned IP address—During the authorization phase of IPCP address negotiation, TACACS+ can return an IP address that the user being authenticated on a dialup interface can use. This address overrides any default IP address and prevents pooling.
- DHCP-retrieved IP address—If configured, the devices acts as proxy clients for the dialup user and retrieve an IP address from a DHCP server. That address is returned to the DHCP server when the timer expires or when the interface goes down.
- Local address pool—The local address pool contains a set of contiguous IP addresses (a maximum of 1024 addresses) stored in two queues. The free queue contains the addresses that are available to be assigned, and the used queue contains addresses that are in use. Addresses are stored to the free queue in the FIFO order to minimize the chance the address will be reused and to allow a peer to reconnect using the same address that it used in the last connection. If the address is available, it is assigned; if not, another address from the free queue is assigned.
Precedence Rules
The following precedence rules of peer IP address support determine which address is used. Precedence is listed from most likely to least likely.
- AAA/TACACS+-provided address or addresses from the pool named by AAA/TACACS+
- An address from a local IP address pool or DHCP (typically not allocated unless no other address exists)
- Configured address from the peer default ip address command or address from the protocol translate command
- Peer-provided address from IPCP negotiation (not accepted unless no other address exists)
Interfaces Affected
Address pooling is available on all asynchronous serial interfaces and synchronous serial interfaces that are running PPP.
Multilink PPP Interleaving and Queueing
Interleaving on Multilink PPP allows large packets to be multilink encapsulated and fragmented into a small enough size to satisfy the delay requirements of real-time traffic; small real-time packets are not multilink encapsulated and are sent between the fragments of large packets. The interleaving feature also provides a special transmit queue for the smaller, delay-sensitive packets, enabling them to be sent earlier than other flows.
Weighted fair queueing on Multilink PPP works at the packet level, not at the level of multilink fragments. Thus, if a small, real-time packet gets queued behind a larger, best-effort packet and no special queue has been reserved for real-time packets, the small packet will be scheduled for transmission only after all fragments of the larger packet are scheduled for transmission.
Weighted fair queueing is supported on all interfaces that support Multilink PPP, including Multilink PPP virtual access interfaces and virtual interface templates. Weighted fair queueing is enabled by default.
Interleaving applies only to interfaces that can configure a multilink bundle interface.
Multilink PPP and weighted fair queueing are not supported when a multilink bundle is offloaded to a different system using Multichassis Multilink PPP. Thus, interleaving is not supported in Multichassis Multilink PPP networking designs.
How to Configure Media-Independent PPP and Multilink PPP
- Enabling PPP Encapsulation
- Enabling CHAP or PAP Authentication
- Enabling Link Quality Monitoring
- Configuring Compression of PPP Data
- Configuring MPPC
- Configuring IP Address Pooling
- Configuring PPP Reliable Link
- Disabling or Reenabling Peer Neighbor Routes
- Configuring Multilink PPP
- Configuring Multilink PPP Interleaving and Queueing
- Monitoring and Maintaining PPP and Multilink PPP Interfaces
Enabling PPP Encapsulation
The encapsulation ppp command enables PPP on serial lines to encapsulate IP and other network protocol datagrams.
1.
enable
2.
configure
terminal
3.
interface
fastethernet
number
4.
encapsulation
ppp
5.
end
DETAILED STEPS
Enabling CHAP or PAP Authentication
 Caution | If you use a list name that has not been configured with the aaa authentication ppp command, disable PPP on the line. |
1.
enable
2.
configure
terminal
3.
interface
fastethernet
number
4.
ppp
authentication
{chap |
chap
pap |
pap
chap |
pap} [if-needed] [list-name |
default] [callin]
6.
exit
7.
username
name
[user-maxlinks
link-number]
password
secret
8.
end
DETAILED STEPS
Enabling Link Quality Monitoring
Link Quality Monitoring (LQM) is available on all serial interfaces running PPP. LQM monitors the link quality. If the quality drops below a configured percentage, the router shuts down the link. The percentages are calculated for both incoming and outgoing directions. The outgoing quality is calculated by comparing the total number of packets and bytes sent with the total number of packets and bytes received by the destination node. The incoming quality is calculated by comparing the total number of packets and bytes received with the total number of packets and bytes sent by the destination peer.
Note | LQM is not compatible with Multilink PPP. |
When LQM is enabled, every keepalive period is sent to Link Quality Reports (LQRs) in place of keepalives. All incoming keepalives are responded to properly. If LQM is not configured, keepalives are sent every keepalive period and all incoming LQRs are responded to with an LQR.
LQR is specified in RFC 1989, PPP Link Quality Monitoring.
Perform this task to enable LQM on an interface.
1.
enable
2.
configure
terminal
3.
interface
fastethernet
number
4.
ppp
quality
percentage
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
fastethernet
number
Example: Device(config)# interface fastethernet 0/0 |
Enters interface configuration mode. |
| Step 4 |
ppp
quality
percentage
Example: Device(config-if)# ppp quality 10 |
Enables LQM on an interface. |
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and enters privileged EXEC mode. |
Configuring Compression of PPP Data
You can configure point-to-point software compression on serial interfaces that use PPP encapsulation. Compression reduces the size of a PPP frame through lossless data compression. PPP encapsulations support both predictor and Stacker compression (STAC) algorithms.
If most of your traffic is already compressed files, do not use compression.
Software compression is available on all router platforms. Software compression is performed by the main processor in the router.
Compression is performed in software and might significantly affect system performance. We recommend that you disable compression if the router CPU load exceeds 65 percent. To display the CPU load, use the show process cpu command.
1.
enable
2.
configure
terminal
3.
interface
fastethernet
number
4.
encapsulation
ppp
5.
compress
[predictor |
stac |
mppc [ignore-pfc]]
6.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
fastethernet
number
Example: Device(config)# interface fastethernet 0/0 |
Enters interface configuration mode. |
| Step 4 |
encapsulation
ppp
Example: Device(config-if)# encapsulation ppp |
Enables encapsulation of a single protocol on the serial line. |
| Step 5 |
compress
[predictor |
stac |
mppc [ignore-pfc]]
Example: Device(config-if)# compress predictor |
Enables compression. |
| Step 6 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Configuring MPPC
Perform this task to configure MPCC. This will help you set MPPC after PPP encapsulation is configured on the device.
Ensure that PPP encapsulation is enabled before you configure MPPC.
Note | The following restrictions apply to the MPPC feature:
|
1.
enable
2.
configure
terminal
3.
interface
serial
number
4.
compress [mppc [ignore-pfc]]
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
serial
number
Example: Device(config)# interface serial 2/0 |
Enters interface configuration mode. |
| Step 4 |
compress [mppc [ignore-pfc]]
Example: Device(config-if)# compress mppc |
Enables encapsulation of a single protocol on the serial line. |
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Example
The following is sample output from the debug ppp negotiation command showing protocol reject:
PPP Async2: protocol reject received for protocol = 0x2145 PPP Async2: protocol reject received for protocol = 0x2145 PPP Async2: protocol reject received for protocol = 0x2145
Configuring IP Address Pooling
- Choosing the IP Address Assignment Method
- Defining the Global Default Address Pooling Mechanism
- Configuring IP Address Assignment
Choosing the IP Address Assignment Method
The IP Address Pooling feature allows the configuration of a global default address pooling mechanism, per-interface configuration of the address pooling mechanism, and per-interface configuration of a specific address or pool name.
You can define the type of IP address pooling mechanism used on router interfaces in one or both of the ways described in the subsequent sections.
Defining the Global Default Address Pooling Mechanism
The global default mechanism applies to all point-to-point interfaces that support PPP encapsulation and that have not otherwise been configured for IP address pooling. You can define the global default mechanism to be either DHCP or local address pooling.
After you have defined a global default mechanism, you can disable it on a specific interface by configuring the interface for some other pooling mechanism. You can define a local pool other than the default pool for the interface or you can configure the interface with a specific IP address to be used for dial-in peers.
- Defining DHCP as the Global Default Mechanism
- Defining Local Address Pooling as the Global Default Mechanism
- Controlling DHCP Network Discovery
Defining DHCP as the Global Default Mechanism
DHCP specifies the following components:
- A DHCP server—A host-based DHCP server configured to accept and process requests for temporary IP addresses.
- A DHCP proxy-client—A Cisco access server configured to arbitrate DHCP calls between the DHCP server and the DHCP client. The DHCP Client Proxy feature manages a pool of IP addresses available to dial-in clients without a known IP address.
Perform this task to define DHCP as the global default mechanism.
1.
enable
2.
configure
terminal
3.
ip
address-pool
dhcp-proxy-client
4.
ip dhcp-server
[ip-address |
name]
5.
end
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
ip
address-pool
dhcp-proxy-client
Example: Device(config)# ip address-pool dhcp-proxy-client |
Specifies the DHCP Client Proxy feature as the global default mechanism.
| ||
| Step 4 |
ip dhcp-server
[ip-address |
name]
Example: Device(config)# ip dhcp-server 209.165.201.1 |
(Optional) Specifies the IP address of a DHCP server for the proxy client to use. | ||
| Step 5 |
end
Example: Device(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Defining Local Address Pooling as the Global Default Mechanism
Note | If no other pool is defined, a local pool called “default” is used. Optionally, you can associate an address pool with a named pool group. |
1.
enable
2.
configure
terminal
3.
ip
address-pool
local
4.
ip
local
pool
{named-address-pool |
default}
first-ip-address [last-ip-address] [group
group-name] [cache-size
size]
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
address-pool
local
Example: Device(config)# ip address-pool local |
Specifies local address pooling as the global default mechanism. |
| Step 4 |
ip
local
pool
{named-address-pool |
default}
first-ip-address [last-ip-address] [group
group-name] [cache-size
size]
Example: Device(config)# ip local pool default 192.0.2.1 |
Creates one or more local IP address pools. |
| Step 5 |
end
Example: Device(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Controlling DHCP Network Discovery
Perform this task to allow peer routers to dynamically discover Domain Name System (DNS) and NetBIOS name server information configured on a DHCP server by using PPP IP Control Protocol (IPCP) extensions.
The ip dhcp-client network-discovery global configuration command provides a way to control the DHCP network discovery mechanism. The number of DHCP Inform or Discovery messages can be set to 1 or 2, which determines the number of times the system sends the DHCP Inform or Discover messages before stopping network discovery. You can set a timeout period from 3 to 15 seconds or leave the default timeout period at 15 seconds. The default value for the informs and discovers keywords is 0, which disables the transmission of these messages.
1.
enable
2.
configure
terminal
3.
ip
dhcp-client
network-discovery
informs
number-of-messages
discovers
number-of-messages
period
seconds
4.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
dhcp-client
network-discovery
informs
number-of-messages
discovers
number-of-messages
period
seconds
Example: Device(config)# ip dhcp-client network-discovery informs 2 discovers 2 period 2 |
Provides control of the DHCP network discovery mechanism by allowing the specified number of DHCP Inform and Discover messages to be sent and a timeout period for retransmission to be configured. |
| Step 4 |
end
Example: Device(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Configuring IP Address Assignment
After you have defined a global default mechanism for assigning IP addresses to dial-in peers, you can configure the few interfaces for which it is important to have a nondefault configuration. You can do one of the following:
- Define a nondefault address pool for use by a specific interface.
- Define DHCP on an interface even if you have defined local pooling as the global default mechanism.
- Specify one IP address to be assigned to all dial-in peers on an interface.
- Make temporary IP addresses available on a per-interface basis to asynchronous clients by using SLIP or PPP.
Perform this task to define a nondefault address pool for use on an interface.
1.
enable
2.
configure
terminal
3.
ip
local
pool
{named-address-pool |
default} {first-ip-address [last-ip-address]} [group
group-name] [cache-size
size]}
4.
interface
type
number
5.
peer
default
ip
address
pool
pool-name-list
6.
peer
default
ip
address
pool
dhcp
7.
peer
default
ip
address
ip-address
8.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ip
local
pool
{named-address-pool |
default} {first-ip-address [last-ip-address]} [group
group-name] [cache-size
size]}
Example: Device(config)# ip local pool default 192.0.2.0 |
Creates one or more local IP address pools. |
| Step 4 |
interface
type
number
Example: Device(config)# interface ethernet 2/0 |
Specifies the interface and enters interface configuration mode. |
| Step 5 |
peer
default
ip
address
pool
pool-name-list
Example: Device(config-if)# peer default ip address pool 2 |
Specifies the pool or pools for the interface to use. |
| Step 6 |
peer
default
ip
address
pool
dhcp
Example: Device(config-if)# peer default ip address pool dhcp |
Specifies DHCP as the IP address mechanism on this interface. |
| Step 7 |
peer
default
ip
address
ip-address
Example: Device(config-if)# peer default ip address 192.0.2.2 |
Specifies the IP address to assign to all dial-in peers on an interface. |
| Step 8 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Configuring PPP Reliable Link
PPP reliable link is Cisco’s implementation of RFC 1663, PPP Reliable Transmission, which defines a method of negotiating and using Numbered Mode Link Access Procedure, Balanced (LAPB) to provide a reliable serial link. Numbered Mode LAPB provides retransmission of error packets across a serial link.
Although the LAPB protocol overhead consumes some bandwidth, you can offset the bandwidth consumption by the use of PPP compression over a reliable link. PPP compression is separately configurable and is not required for use by a reliable link.
Note | PPP reliable link is available only on synchronous serial interfaces. PPP reliable link cannot be used over V.120 and does not work with Multilink PPP. |
Perform this task to configure PPP reliable link on the specified interface.
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
ppp
reliable-link
5.
end
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
interface
type
number
Example: Device(config)# interface ethernet 2/0 |
Specifies the interface and enters interface configuration mode. | ||
| Step 4 |
ppp
reliable-link
Example: Device(config-if)# peer default ip address pool 2 |
Enables PPP reliable link.
| ||
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Troubleshooting PPP
You can troubleshoot PPP reliable link by using the following commands:
You can determine whether LAPB has been established on a connection by using the show interface command.
Disabling or Reenabling Peer Neighbor Routes
Cisco software automatically creates neighbor routes by default; that is, it automatically sets up a route to the peer address on a point-to-point interface when the PPP IPCP negotiation is completed. Perform this task to disable this default behavior or to reenable it after it has been disabled.
1.
enable
2.
configure
terminal
3.
interface
type
number
4.
no peer neighbor-route
5.
peer
neighbor-route
6.
end
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
interface
type
number
Example: Device(config)# interface ethernet 0/1 |
Specifies the interface and enters interface configuration mode. | ||
| Step 4 |
no peer neighbor-route
Example: Device(config-if)# no peer neighbor-route |
Disables the creation of neighbor routes. | ||
| Step 5 |
peer
neighbor-route
Example: Device(config-if)# peer neighbor-route |
Reenables the creation of neighbor routes.
| ||
| Step 6 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Configuring Multilink PPP
- Configuring Multilink PPP on Synchronous Interfaces
- Creating a Multilink Bundle
- Assigning an Interface to a Multilink Bundle
- Configuring Multilink PPP Using Multilink Group Interfaces
- Configuring Multilink PPP Minimum Links Mandatory
- Changing the Default Endpoint Discriminator
Configuring Multilink PPP on Synchronous Interfaces
To configure Multilink PPP on synchronous interfaces, you configure the synchronous interfaces to support PPP encapsulation and Multilink PPP.
1.
enable
2.
configure
terminal
3.
interface
serial
number
4.
no
ip
address
5.
encapsulation
ppp
6.
ppp
multilink
7.
pulse-time
seconds
8.
end
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
interface
serial
number
Example: Device(config)# interface serial 1
|
Specifies an asynchronous interface and enters interface configuration mode. | ||
| Step 4 |
no
ip
address
Example: Device(config-if)# no ip address |
Specifies no IP address for the interface. | ||
| Step 5 |
encapsulation
ppp
Example: Device(config-if)# encapsulation ppp |
Enables PPP encapsulation. | ||
| Step 6 |
ppp
multilink
Example: Device(config-if)# ppp multilink |
Enables Multilink PPP. | ||
| Step 7 |
pulse-time
seconds
Example: Device(config-if)# pulse-time 60 |
Enables pulsing data terminal ready (DTR) signal intervals on an interface.
| ||
| Step 8 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Creating a Multilink Bundle
1.
enable
2.
configure
terminal
3.
interface
multilink
group-number
4.
ip
address
address
mask
5.
encapsulation
ppp
6.
ppp
multilink
7.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
multilink
group-number
Example: Device(config)# interface multilink 10 |
Assigns a multilink group number and enters interface configuration mode. |
| Step 4 |
ip
address
address
mask
Example: Device(config-if)# ip address 192.0.2.9 255.255.255.224 |
Assigns an IP address to the multilink interface. |
| Step 5 |
encapsulation
ppp
Example: Device(config-if)# encapsulation ppp |
Enables PPP encapsulation. |
| Step 6 |
ppp
multilink
Example: Device(config-if)# ppp multilink |
Enables Multilink PPP. |
| Step 7 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Assigning an Interface to a Multilink Bundle
Caution | Do not install a device to the peer address while configuring an MLPP lease line. This can be disabled using the no ppp peer-neighbor-route command under the MLPPP bundle interface. |
1.
enable
2.
configure
terminal
3.
interface
multilink
group-number
4.
no
ip
address
5.
keepalive
6.
encapsulation
ppp
7.
ppp
multilink
group
group-number
8.
ppp
multilink
9.
ppp
authentication
chap
10.
pulse-time
seconds
11.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
multilink
group-number
Example: Device(config)# interface multilink 10 |
Assigns a multilink group number and enters interface configuration mode. |
| Step 4 |
no
ip
address
Example: Device(config-if)# no ip address |
Removes any specified IP address. |
| Step 5 |
keepalive
Example: Device(config-if)# keepalive |
Sets the frequency of keepalive packets. |
| Step 6 |
encapsulation
ppp
Example: Device(config-if)# encapsulation ppp |
Enables PPP encapsulation. |
| Step 7 |
ppp
multilink
group
group-number
Example: Device(config-if)# ppp multilink 12 |
Restricts a physical link to join only the designated multilink group interface. |
| Step 8 |
ppp
multilink
Example: Device(config-if)# ppp multilink |
Enables Multilink PPP. |
| Step 9 |
ppp
authentication
chap
Example: Device(config-if)# ppp authentication chap |
(Optional) Enables CHAP authentication. |
| Step 10 |
pulse-time
seconds
Example: Device(config-if)# pulse-time 10 |
(Optional) Configures DTR signal pulsing. |
| Step 11 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Configuring Multilink PPP Using Multilink Group Interfaces
Multilink PPP can be configured by assigning a multilink group to a virtual template configuration. Virtual templates allow a virtual access interface to dynamically clone interface parameters from the specified virtual template. If a multilink group is assigned to a virtual template and then the virtual template is assigned to a physical interface, all links that pass through the physical interface will belong to the same multilink bundle.
Note | If a multilink group interface has one member link, the amount of bandwidth available will not change when a multilink interface is shut down. Therefore, you can shut down the multilink interface by removing its link. |
A multilink group interface configuration will override a global multilink virtual template configured using the multilink virtual template command.
Multilink group interfaces can be used with ATM, PPP over Frame Relay, and serial interfaces.
To configure Multilink PPP using a multilink group interface, perform the following tasks:
1.
enable
2.
configure
terminal
3.
interface
multilink
group-number
4.
ip
address
address
mask
5.
encapsulation
ppp
6.
exit
7.
interface
virtual
template
number
8.
ppp
multilink
group
group-number
9.
exit
10.
interface
atm
interface-number.subinterface-number
point-to-point
11.
pvc
vpi/vci
12.
protocol
ppp
virtual-template
name
13.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
multilink
group-number
Example: Device(config)# interface multilink 2 |
Creates a multilink bundle and enters interface configuration mode. |
| Step 4 |
ip
address
address
mask
Example: Device(config-if)# ip address 192.0.2.1 255.255.255.224 |
Sets a primary IP address for an interface. |
| Step 5 |
encapsulation
ppp
Example: Device(config-if)# encapsulation ppp |
Enables PPP encapsulation. |
| Step 6 |
exit
Example: Device(config-if)# exit |
Exits interface configuration mode and enters global configuration mode. |
| Step 7 |
interface
virtual
template
number
Example: Device(config)# interface virtual template 1 |
Creates a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces and enters interface configuration mode. |
| Step 8 |
ppp
multilink
group
group-number
Example: Device(config-if)# ppp multilink group 2 |
Restricts a physical link to join only a designated multilink group interface. |
| Step 9 |
exit
Example: Device(config-if)# exit |
Exits interface configuration mode and enters global configuration mode. |
| Step 10 |
interface
atm
interface-number.subinterface-number
point-to-point
Example: Device(config)# interface atm 1.2 point-to-point |
Configures an ATM interface and enters interface configuration mode. |
| Step 11 |
pvc
vpi/vci
Example: Device(config-if)# pvc 1/100 |
Creates or assigns a name to an ATM permanent virtual circuit (PVC), specifies the encapsulation type on an ATM PVC, and enters ATM virtual circuit configuration mode. |
| Step 12 |
protocol
ppp
virtual-template
name
Example: Device(config-if-atm-vc)# protocol ppp virtual-template 2 |
Configures VC multiplexed encapsulation on a PVC. |
| Step 13 |
end
Example: Device(config-if-atm-vc)# end |
Exits ATM virtual circuit configuration mode and returns to privileged EXEC mode. |
Configuring Multilink PPP Minimum Links Mandatory
Perform this task to configure the minimum number of links in a Multilink PPP bundle required to keep that bundle active.
1.
enable
2.
configure
terminal
3.
ppp
multilink
4.
ppp
multilink
min-links
links
mandatory
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
ppp
multilink
Example: Device(config-if)# ppp multilink |
Enables Multilink PPP. |
| Step 4 |
ppp
multilink
min-links
links
mandatory
Example: Device(config-if)# ppp multilink min-links 5 mandatory |
Specifies the required minimum number of links in a Multilink PPP bundle. |
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Changing the Default Endpoint Discriminator
By default, when a system negotiates the use of Multilink PPP with a peer, the value that is supplied for the endpoint discriminator is the same as the username used for authentication. The username is configured for the interface by the ppp chap hostname or ppp pap sent-username command, or the username defaults to the globally configured hostname (or stack group name if this interface is a Stack Group Bidding Protocol (SGBP) group member).
Perform this task to override or change the default endpoint discriminator.
1.
enable
2.
configure
terminal
3.
interface
virtual-template
number
4.
ppp
multilink
endpoint
{hostname |
ip
ipaddress |
mac
LAN-interface |
none |
phone
telephone-number |
string
char-string}
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
virtual-template
number
Example: Device(config)# interface virtual-template 1 |
Creates a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces and enters interface configuration mode. |
| Step 4 |
ppp
multilink
endpoint
{hostname |
ip
ipaddress |
mac
LAN-interface |
none |
phone
telephone-number |
string
char-string}
Example: Device(config-if)# ppp multilink endpoint ip 192.0.2.0 |
Overrides or changes the default endpoint discriminator that a system uses when negotiating the use of Multilink PPP with a peer. |
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Configuring Multilink PPP Interleaving and Queueing
Multilink PPP support for interleaving can be configured on virtual templates. To configure interleaving, complete the following tasks:
- Configure a virtual template.
- Configure Multilink PPP and interleaving on the interface or template.
Note | Fair queueing, which is enabled by default, must remain enabled on the interface. |
Configuring Multilink PPP Interleaving
Note | Interleaving statistics can be displayed by using the show interfaces command, specifying the particular interface on which interleaving is enabled. Interleaving data is displayed only if there are interleaves. For example, the following line shows interleaves: Output queue: 315/64/164974/31191 (size/threshold/drops/interleaves) |
1.
enable
2.
configure
terminal
3.
interface
virtual-template
number
4.
ppp
multilink
5.
ppp
multilink
interleave
6.
ppp
multilink
fragment
delay
milliseconds
7.
ip
rtp
reserve
lowest-udp-port
range-of-ports
[maximum-bandwidth]
8.
exit
9.
multilink
virtual-template
virtual-template-number
10.
end
DETAILED STEPS
| Command or Action | Purpose | |||
|---|---|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. | ||
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. | ||
| Step 3 |
interface
virtual-template
number
Example: Device(config)# interface virtual-template 1 |
Creates a virtual template interface that can be configured and applied dynamically in creating virtual access interfaces and enters interface configuration mode. | ||
| Step 4 |
ppp
multilink
Example: Device(config-if)# ppp multilink |
Enables Multilink PPP. | ||
| Step 5 |
ppp
multilink
interleave
Example: Device(config-if)# configure terminal |
Enables interleaving of packets among the fragments of larger packets on a Multilink PPP bundle. | ||
| Step 6 |
ppp
multilink
fragment
delay
milliseconds
Example: Device(config-if)# ppp multilink fragment delay 50 |
Specifies a maximum size, in units of time, for packet fragments on a Multilink PPP bundle. | ||
| Step 7 |
ip
rtp
reserve
lowest-udp-port
range-of-ports
[maximum-bandwidth]
Example: Device(config-if)# ip rtp reserve 1 2 |
Reserves a special queue for real-time packet flows to specified destination UDP ports, allowing real-time traffic to have higher priority than other flows. | ||
| Step 8 |
exit
Example: Device(config-if)# exit |
Exits interface configuration mode and enters global configuration mode. | ||
| Step 9 |
multilink
virtual-template
virtual-template-number
Example: Device(config)# multilink virtual-template 1 |
For virtual templates only, applies the virtual template to the multilink bundle.
| ||
| Step 10 |
end
Example: Device(config)# end |
Exits global configuration mode and returns to privileged EXEC mode. |
Disabling PPP Multilink Fragmentation
1.
enable
2.
configure
terminal
3.
interface
multilink
group-number
4.
ppp
multilink
fragment
disable
5.
end
DETAILED STEPS
| Command or Action | Purpose | |
|---|---|---|
| Step 1 |
enable
Example: Device> enable |
Enables privileged EXEC mode. |
| Step 2 |
configure
terminal
Example: Device# configure terminal |
Enters global configuration mode. |
| Step 3 |
interface
multilink
group-number
Example: Device(config)# interface multilink 10 |
Assigns a multilink group number and enters interface configuration mode. |
| Step 4 |
ppp
multilink
fragment
disable
Example: Device(config-if)# ppp multilink fragment disable |
(Optional) Disables PPP multilink fragmentation. |
| Step 5 |
end
Example: Device(config-if)# end |
Exits interface configuration mode and returns to privileged EXEC mode. |
Monitoring and Maintaining PPP and Multilink PPP Interfaces
Perform this task to display Multilink PPP and Multichassis Multilink PPP bundle information.
1.
enable
2.
show
ppp
multilink
3.
exit
DETAILED STEPS
| Command or Action | Purpose |
|---|
Configuration Examples for PPP and Multilink PPP
- Example: Configuring Multilink PPP with Traffic Shaping
- Example: Enabling CHAP Authentication with an Encrypted Password
- Example: Configuring Multilink PPP on Synchronous Serial Interfaces
- Example: Configuring Multilink PPP Using Multilink Group Interfaces over ATM
- Example: Configuring Multilink PPP Interleaving and Queueing for Real-Time Traffic
Example: Configuring Multilink PPP with Traffic Shaping
The following example shows how to configure Multilink PPP with traffic shaping and quality of service (QoS). In this example, two bundles with four links in each bundle are configured between two devices. The ppp chap hostname command entries are required for originating and terminating multiple bundles on a single pair of devices.
controller T3 0/3/1
framing c-bit
cablelength 224
t1 1 channel-group 0 timeslots 1-24
t1 2 channel-group 0 timeslots 1-24
t1 3 channel-group 0 timeslots 1-24
t1 4 channel-group 0 timeslots 1-24
t1 5 channel-group 0 timeslots 1-24
t1 6 channel-group 0 timeslots 1-24
t1 7 channel-group 0 timeslots 1-24
t1 8 channel-group 0 timeslots 1-24
!
class-map match-all DETERMINISTICOUT
match ip precedence 3
class-map match-all VOICEVIDEOCONTROLOUT
match ip precedence 2
class-map match-all VOICEOUT
match ip precedence 1
class-map match-all ROUTINGPROTOCOLS
match ip precedence 5
class-map match-all CONTROLLEDLOADOUT
match ip precedence 4
!
policy-map QOS304QCHILD
class VOICEOUT
priority level 1
police cir percent 30
class VOICEVIDEOCONTROLOUT
priority level 2
police cir percent 5
class DETERMINISTICOUT
bandwidth remaining ratio 20
class CONTROLLEDLOADOUT
bandwidth remaining ratio 18
class ROUTINGPROTOCOLS
bandwidth remaining ratio 4
class class-default
bandwidth remaining ratio 22
policy-map ASRMLPPP6MBPARENT
class class-default
shape average percent 98
service-policy QOS304QCHILD
!
interface Multilink1
ip address 192.168.1.1 255.255.255.0
ppp chap hostname multilink_name-1
ppp multilink
ppp multilink group 1
service-policy output ASRMLPPP6MBPARENT
!
interface Multilink2
ip address 192.168.2.1 255.255.255.0
ppp chap hostname multilink_name-2
ppp multilink
ppp multilink group 2
service-policy output ASRMLPPP6MBPARENT
!
interface serial 0/3/1/1:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-1
ppp multilink
ppp multilink group 1
!
interface serial 0/3/1/2:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-1
ppp multilink
ppp multilink group 1
!
interface serial 0/3/1/3:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-1
ppp multilink
ppp multilink group 1
!
interface serial 0/3/1/4:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-1
ppp multilink
ppp multilink group 1
!
interface serial 0/3/1/5:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-2
ppp multilink
ppp multilink group 2
!
interface serial 0/3/1/6:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-2
ppp multilink
ppp multilink group 2
!
interface serial 0/3/1/7:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-2
ppp multilink
ppp multilink group 2
!
interface serial 0/3/1/8:0
no ip address
encapsulation ppp
no keepalive
ppp chap hostname multilink_name-2
ppp multilink
ppp multilink group 2
!
Example: Enabling CHAP Authentication with an Encrypted Password
The following examples show how to enable CHAP on serial interface 0 of three devices:
Configuration of Router yyy
hostname yyy interface serial 0/0/0 encapsulation ppp ppp authentication chap username xxx password secretxy username zzz password secretzy
Configuration of Router xxx
hostname xxx interface serial 0/0/0 encapsulation ppp ppp authentication chap username yyy password secretxy username zzz password secretxz
Configuration of Router zzz
hostname zzz interface serial 0/0/0 encapsulation ppp ppp authentication chap username xxx password secretxz username yyy password secretzy
When you look at the configuration file, the passwords will be encrypted and the display will look similar to the following:
hostname xxx interface serial 0/0/0 encapsulation ppp ppp authentication chap username yyy password 7 121F0A18 username zzz password 7 1329A055
Example: Configuring Multilink PPP on Synchronous Serial Interfaces
Multilink PPP provides characteristics most similar to hardware inverse multiplexers, with good manageability and Layer 3 services support. The figure below shows a typical inverse multiplexing application using two Cisco routers and Multilink PPP over four T1 lines.
The following example shows the configuration commands that are used to create the inverse multiplexing application:
Router A Configuration
hostname RouterA ! ! username RouterB password your_password ip subnet-zero multilink virtual-template 1 ! interface virtual-template 1 ip unnumbered Ethernet 0 ppp authentication chap ppp multilink ! interface serial0 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial1 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial2 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial3 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface GigabitEthernet0/0/0 ip address 10.17.1.254 255.255.255.0 ! router rip network 10.0.0.0 ! end
Router B Configuration
hostname RouterB ! ! username RouterB password your_password ip subnet-zero multilink virtual-template 1 ! interface virtual-template 1 ip unnumbered Ethernet0 ppp authentication chap ppp multilink ! interface serial0 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial1 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial2 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface serial3 no ip address encapsulation ppp no fair-queue ppp multilink pulse-time 3 ! interface Ethernet0 ip address 10.17.2.254 255.255.255.0 ! router rip network 10.0.0.0 ! end
Example: Configuring Multilink PPP Using Multilink Group Interfaces over ATM
The following example shows how to configure Multilink PPP over an ATM PVC using a multilink group:
interface multilink 1 ip address 10.200.83.106 255.255.255.252 ip tcp header-compression iphc-format delay 20000 service policy output xyz encapsulation ppp ppp multilink ppp multilink fragment delay 10 ppp multilink interleave ppp timeout multilink link remove 10 ip rtp header-compression iphc-format interface virtual-template 3 bandwidth 128 ppp multilink group 1 interface atm 4/0.1 point-to-point pvc 0/32 abr 100 80 protocol ppp virtual-template 3
Example: Configuring Multilink PPP Interleaving and Queueing for Real-Time Traffic
The following example shows how to define a virtual interface template that enables Multilink PPP interleaving with a maximum real-time traffic delay of 20 milliseconds and then applies the virtual template to the Multilink PPP bundle:
interface virtual-template 1 ip unnumbered ethernet 0 ppp multilink ppp multilink interleave ppp multilink fragment delay 20 ip rtp interleave 32768 20 1000 multilink virtual-template 1
Additional References
Related Documents
|
Related Topic |
Document Title |
|---|---|
Cisco IOS commands |
|
|
PPP commands |
|
|
Wide-area networking commands |
MIBs
|
MIB |
MIBs Link |
|---|---|
No MIBs were introduced or modified for this feature. |
To locate and download MIBs for selected platforms, Cisco IOS XE software releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for Media-Independent PPP and Multilink PPP
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
|
Feature Name |
Releases |
Feature Information |
|---|---|---|
|
Media-Independent PPP and Multilink PPP |
Cisco IOS XE Release 2.1 |
This feature was introduced on Cisco ASR 1000 Series Routers. |
|
Multilink PPP Minimum Links Mandatory |
Cisco IOS XE Release 2.1 |
The Multilink PPP Minimum Links Mandatory feature enables you to configure the minimum number of links in a MLP bundle required to keep that bundle active. The following commands were introduced or modified: multilink min-links, ppp multilink links minimum. |
|
DHCP Proxy Client |
Cisco IOS XE Release 2.3 |
The DHCP proxy client feature allows you to manage a pool of IP addresses available to PPP or SLIP dial-in clients without a known IP address. |