Cisco Systems 78-11741-02 manual Assigning Options to the Peer Group, IPC-321

Configuring BGP

Configuring Advanced BGP Features

Assigning Options to the Peer Group

After you create a peer group, you configure the peer group with neighbor commands. By default, members of the peer group inherit all the configuration options of the peer group. Members can also be configured to override the options that do not affect outbound updates.

Peer group members will always inherit the following attributes: minimum-advertisement-interval, next-hop-self, out-route-map, out-filter-list, out-dist-list, remote-as (if configured), version, and update-source. All the peer group members will inherit changes made to the peer group.

To assign configuration options to an individual neighbor, specify any of the following commands using the IP address. To assign the options to a peer group, specify any of the commands using the peer group name. Use the following commands in router configuration mode as needed.

Command		Purpose
Router(config-router)# neighbor	{ip-address	Specifies a BGP neighbor.
peer-group-name}remote-asas-number
Router(config-router)# neighbor	{ip-address	Associates a description with a neighbor.
peer-group-name}description text
Router(config-router)# neighbor	{ip-address	Allows a BGP speaker (the local router) to send the default
peer-group-name}default-originate [route-map		route 0.0.0.0 to a neighbor for use as a default route.
map-name]
Router(config-router)# neighbor	{ip-address	Specifies that the communities attribute be sent to the
peer-group-name}send-community		neighbor at this IP address.
Router(config-router)# neighbor	{ip-address	Allows iBGP sessions to use any operational interface for
peer-group-name}update-sourceinterface-type		TCP connections.
Router(config-router)# neighbor	{ip-address	Allows BGP sessions, even when the neighbor is not on a
peer-group-name}ebgp-multihop		directly connected segment. The multihop session is not
		established if the only route to the address of the multihop
		peer is the default route (0.0.0.0).
Router(config-router)# neighbor	{ip-address	Sets the minimum interval between sending BGP routing
peer-group-name}advertisement-interval seconds		updates.
Router(config-router)# neighbor	{ip-address	Limits the number of prefixes allowed from a neighbor.
peer-group-name}maximum-prefix	maximum [threshold]
[warning-only]
Router(config-router)# neighbor	{ip-address	Specifies a weight for all routes from a neighbor.
peer-group-name}weight weight
Router(config-router)# neighbor	{ip-address	Filters BGP routing updates to and from neighbors, as
peer-group-name}distribute-list{access-list-number		specified in an access list.
access-list-name} {in out}
Router(config-router)# neighbor	{ip-address	Establishes a BGP filter.
peer-group-name}filter-listaccess-list-number {in
out weight weight}
Router(config-router)# neighbor	{ip-address	Disables next hop processing on the BGP updates to a
peer-group-name}next-hop-self		neighbor.
Router(config-router)# neighbor	{ip-address	Specifies the BGP version to use when communicating with
peer-group-name}version value		a neighbor.

Cisco IOS IP Configuration Guide

IPC-321