Cisco 3560G 48TS Software Configuration Guide - Page 665

Chapter 30 Configuring IP Unicast Routing Configuring BGP Configuring BGP Neighbors and Peer Groups Often many BGP neighbors are configured with the same update policies (that is, the same outbound route maps, distribute lists, filter lists, update source, and so on). Neighbors with the same update policies can be grouped into peer groups to simplify configuration and to make updating more efficient. When you have configured many peers, we recommend this approach. To configure a BGP peer group, you create the peer group, assign options to the peer group, and add neighbors as peer group members. You configure the peer group by using the neighbor router configuration commands. By default, peer group members inherit all the configuration options of the peer group, including the remote-as (if configured), version, update-source, out-route-map, out-filter-list, out-dist-list, minimum-advertisement-interval, and next-hop-self. All peer group members also inherit changes made to the peer group. Members can also be configured to override the options that do not affect outbound updates. To assign configuration options to an individual neighbor, specify any of these router configuration commands by using the neighbor IP address. To assign the options to a peer group, specify any of the commands by using the peer group name. You can disable a BGP peer or peer group without removing all the configuration information by using the neighbor shutdown router configuration command. Beginning in privileged EXEC mode, use these commands to configure BGP peers: Step 1 Step 2 Step 3 Step 4 Step 5 Command configure terminal router bgp autonomous-system neighbor peer-group-name peer-group neighbor ip-address peer-group peer-group-name neighbor {ip-address | peer-group-name} remote-as number Step 6 Step 7 Step 8 Step 9 Step 10 neighbor {ip-address | peer-group-name} description text neighbor {ip-address | peer-group-name} default-originate [route-map map-name] neighbor {ip-address | peer-group-name} send-community neighbor {ip-address | peer-group-name} update-source interface neighbor {ip-address | peer-group-name} ebgp-multihop Step 11 Step 12 neighbor {ip-address | peer-group-name} local-as number neighbor {ip-address | peer-group-name} advertisement-interval seconds Purpose Enter global configuration mode. Enter BGP router configuration mode. Create a BGP peer group. Make a BGP neighbor a member of the peer group. Specify a BGP neighbor. If a peer group is not configured with a remote-as number, use this command to create peer groups containing EBGP neighbors. The range is 1 to 65535. (Optional) Associate a description with a neighbor. (Optional) Allow a BGP speaker (the local router) to send the default route 0.0.0.0 to a neighbor for use as a default route. (Optional) Specify that the COMMUNITIES attribute be sent to the neighbor at this IP address. (Optional) Allow internal BGP sessions to use any operational interface for TCP connections. (Optional) Allow BGP sessions, even when the neighbor is not on a directly connected segment. The multihop session is not established if the only route to the multihop peer's address is the default route (0.0.0.0). (Optional) Specify an AS number to use as the local AS. The range is 1 to 65535. (Optional) Set the minimum interval between sending BGP routing updates. 78-16156-01 Catalyst 3560 Switch Software Configuration Guide 30-57