3Com Switch 7750 Configuration Guide Guide

Configuring a Large-Scale BGP Network 351
Community can also be used to ease the routing policy management. And its
management range is much wider than that of the peer group. It controls the
routing policy of multiple BGP routers.
In an AS, to ensure the connectivity among IBGP peers, you need to set up full
connection among them. When there are too many IBGP peers, it will cost a lot in
establishing a full connection network. Using RR or confederation can solve the
problem. In a large AS, RR and confederation can be used simultaneously.
Configuration
Prerequisites
Before configuring a large-scale BGP network, you need to ensure:
■ Network layer connectivity between adjacent nodes.
Before configuring a large-scale BGP network, you need to prepare the following
data:
■ Peer group type, name, and the peers included.
■ If you want to use community, the name of the applied routing policy is
needed.
■ If you want to use RR, you need to determine the roles (client, non-client) of
routers.
■ If you want to use confederation, you need to determine the confederation ID
and the sub-AS number.
Configuring BGP Peer
Group
c
CAUTION:
■ It is not required to specify an AS number for creating an IBGP peer group.
Table 284 Configure BGP peer group
Operation Command Description
Enter system view system-view -
Enable BGP, and enter BGP view bgp as-number
Required
By default, the system does not
operate BGP.
Create an
IBGP peer
group
Create an IBGP
peer group
group group-name [
internal ]
Optional
If the command is executed
without the internal or external
keyword, an IBGP peer group will
be created. You can add multiple
peers to the group, and the
system will automatically create a
peer in BGP view, and configure
its AS number as the local AS
number.
Add a peer to a
peer group
peer ip-address group
group-name [
as-number as-number ]
Create an
EBGP peer
group
Create an EBGP
peer group
group group-name
external
Optional
You can add multiple peers to
the group. The system
automatically creates the peer in
BGP view and specifies its AS
number as the one of the peer
group.
Configure the AS
number of a peer
group
peer group-name
as-number as-number