Configuring Peer GroupsTo configure multiple BGP neighbors at one time, create and populate a BGP peer group.An advantage of peer groups is that members of a peer group inherit the configuration properties of the group and share same updatepolicy.A maximum of 256 peer groups are allowed on the system.Create a peer group by assigning it a name, then adding members to the peer group. After you create a peer group, you can configure routepolicies for it. For information about configuring route policies for a peer group, refer to Filtering BGP Routes.NOTE: Sample Configurations for enabling peer groups are found at the end of thischapter.1 Create a peer group by assigning a name to it.CONFIG-ROUTERBGP modeneighbor peer-group-name peer-group2 Enable the peer group.CONFIG-ROUTERBGP modeneighbor peer-group-name no shutdownBy default, all peer groups are disabled.3 Create a BGP neighbor.CONFIG-ROUTERBGP modeneighbor ip-address remote-as as-number4 Enable the neighbor.CONFIG-ROUTERBGP modeneighbor ip-address no shutdown5 Add an enabled neighbor to the peer group.CONFIG-ROUTERBGP modeneighbor ip-address peer-group peer-group-name6 Add a neighbor as a remote AS.CONFIG-ROUTERBGP modeneighbor {ip-address | peer-group name} remote-as as-numberFormats: IP Address A.B.C.D• Peer-Group Name: 16 characters.• as-number: the range is from 0 to 65535 (2-Byte) or 1 to 4294967295 | 0.1 to 65535.65535 (4-Byte) or 0.1 to 65535.65535(Dotted format)To add an external BGP (EBGP) neighbor, configure the as-number parameter with a number different from the BGP as-numberconfigured in the router bgp as-number command.To add an internal BGP (IBGP) neighbor, configure the as-number parameter with the same BGP as-number configured in therouter bgp as-number command.Examples of Viewing and Configuring Peer GroupsAfter you create a peer group, you can use any of the commands beginning with the keyword neighbor to configure that peer group.Border Gateway Protocol IPv4 (BGPv4) 197
