3Com Switch 7750 Configuration Guide

Configuring a Large-Scale BGP Network 365
■ BGP soft reset can refresh the BGP routing table and apply a new routing policy
without breaking the NGP connections.
Configuring a
Large-Scale BGP
Network
In large-scale network, there are large quantities of peers. Configuring and
maintaining the peer becomes a big problem. Using peer group can ease the
management and improve the routes sending efficiency. According to the
different ASs where peers reside, the peer groups fall into IBGP peer groups and
EBGP peer groups. For the EBGP peer group, it can also be divided into pure EBGP
peer group and hybrid EBGP peer group according to whether the peers in the
EBGP group belong to the same exterior AS or not.
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
Table 301 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.