Here's a good link http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a00809d16f0 .shtml#peergroups
"If a peer group member is "in sync", a BGP router takes an update message formatted for the peer group leader and replicates it for the member. It is far more efficient to replicate an update for a peer group member than it is to reformat the update. For example, assume a peer group has 20 members and all members need to receive 100 BGP messages. One hundred percent replication means that a BGP router formats the 100 messages for the peer group leader and replicates those messages to the other 19 peer group members. To confirm replication improvements, compare the number of messages replicated to the number of messages formatted, as shown by the show ip bgp peer-group command. The improvements make a dramatic difference in convergence times and allow BGP to support many more peers. Let's look at an example." Message: 1 Date: Fri, 17 Jul 2009 09:51:41 -0400 From: Robert S Wyzykowski <[email protected]> Subject: [OSL | CCIE_RS] Configuring a BGP Peer Group Improves Convergence Time for the AS? To: [email protected], [email protected] Message-ID: <ofa6fa162f.757c7385-on852575f6.004b1a92-852575f6.004c2...@imerys.com> Content-Type: text/plain; charset="us-ascii" I am working through Version 11, Lab 14, Section 14.1. The task requires to "improve convergence" between the iMBGP peers. The Proctor guide states that configuring peer groups will improve convergence time. (Page 415 of the Proctor Guid, Section 14.1). Can someone elaborate on this please. Thanks. _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
