Caching source-active state – Dell POWEREDGE M1000E User Manual

Page 1148

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45-6

Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide

OL-13270-03

Chapter 45 Configuring MSDP

Configuring MSDP

To remove the default peer, use the no ip msdp default-peer ip-address | name global configuration
command.

This example shows a partial configuration of Router A and Router C in

Figure 45-2

. Each of these ISPs

have more than one customer (like the customer in

Figure 45-2

) who use default peering (no BGP or

MBGP). In that case, they might have similar configurations. That is, they accept SAs only from a default
peer if the SA is permitted by the corresponding prefix list.

Router A

Router(config)# ip msdp default-peer 10.1.1.1

Router(config)# ip msdp default-peer 10.1.1.1 prefix-list site-a

Router(config)# ip prefix-list site-b permit 10.0.0.0/1

Router C

Router(config)# ip msdp default-peer 10.1.1.1 prefix-list site-a

Router(config)# ip prefix-list site-b permit 10.0.0.0/1

Caching Source-Active State

By default, the switch does not cache source/group pairs from received SA messages. When the switch
forwards the MSDP SA information, it does not store it in memory. Therefore, if a member joins a group
soon after a SA message is received by the local RP, that member needs to wait until the next SA
message to hear about the source. This delay is known as join latency.

If you want to sacrifice some memory in exchange for reducing the latency of the source information,
you can configure the switch to cache SA messages.

Step 3

ip prefix-list name [description string] |
seq number {permit | deny} network
length

(Optional) Create a prefix list using the name specified in Step 2.

(Optional) For description string, enter a description of up to 80
characters to describe this prefix list.

For seq number, enter the sequence number of the entry. The range
is 1 to 4294967294.

The deny keyword denies access to matching conditions.

The permit keyword permits access to matching conditions.

For network length, specify the network number and length (in bits)
of the network mask that is permitted or denied.

Step 4

ip msdp description {peer-name |
peer-address} text

(Optional) Configure a description for the specified peer to make it
easier to identify in a configuration or in show command output.

By default, no description is associated with an MSDP peer.

Step 5

end

Return to privileged EXEC mode.

Step 6

show running-config

Verify your entries.

Step 7

copy running-config startup-config

(Optional) Save your entries in the configuration file.

Command

Purpose

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