Configuring Bgp Neighbors And Peer Groups - Cisco WS-C3560-48PS-S Software Configuration Manual

Chapter 30 Configuring IP Unicast Routing

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:
Command
Step 1
configure terminal
Step 2 router bgp autonomous-system
Step 3
neighbor peer-group-name peer-group
Step 4
neighbor ip-address peer-group
peer-group-name
Step 5
neighbor {ip-address | peer-group-name}
remote-as number
Step 6 neighbor {ip-address | peer-group-name}
description text
Step 7 neighbor {ip-address | peer-group-name}
default-originate [route-map map-name]
Step 8 neighbor {ip-address | peer-group-name}
send-community
Step 9
neighbor {ip-address | peer-group-name}
update-source interface
Step 10
neighbor {ip-address | peer-group-name}
ebgp-multihop
Step 11
neighbor {ip-address | peer-group-name}
local-as number
Step 12
neighbor {ip-address | peer-group-name}
advertisement-interval seconds
78-16156-01
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.
Catalyst 3560 Switch Software Configuration Guide
Configuring BGP
30-57