222
Step Command Remarks
3.
Advertise the COMMUNITY
attribute to a peer or peer group.
•
Advertise the COMMUNITY attribute to a
peer or peer group:
peer
{
group-name
|
ip-address
}
advertise-community
•
Advertise the extended community attribute
to a peer or peer group:
peer
{
group-name
|
ip-address
}
advertise-ext-community
Not configured by
default.
4.
Apply a routing policy to routes
advertised to a peer or peer
group.
peer
{
group-name
|
ip-address
}
route-policy
route-policy-name
export
Not configured by
default.
Configuring a BGP route reflector
If an AS has many BGP routers, you can configure them as a cluster by configuring one of them as a route
reflector and others as clients to reduce IBGP connections.
To enhance network reliability and prevent single point of failure, specify multiple route reflectors for a
cluster. The route reflectors in the cluster must have the same cluster ID to avoid routing loops.
It is not required to make clients of a route reflector fully meshed. The route reflector forwards routing
information between clients. If clients are fully meshed, disable route reflection between clients to reduce
routing costs.
Generally, a cluster has only one route reflector, and the router ID is used to identify the cluster. You can
configure multiple route reflectors to improve network stability. To avoid routing loops, specify the same
cluster ID for these route reflectors by using the
reflector cluster-id
command.
To configure a BGP route reflector:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter BGP view.
bgp
as-number
N/A
3.
Configure the router as a route
reflector and specify a peer or
peer group as its client.
peer
{
group-name
|
ip-address
}
reflect-client
Not configured by default.
4.
Enable route reflection
between clients.
reflect between-clients
Optional.
Enabled by default.
5.
Configure the cluster ID of the
route reflector.
reflector cluster-id
cluster-id
Optional.
By default, a route reflector uses its
router ID as the cluster ID.
Configuring a BGP confederation
Configuring a BGP confederation is another way for reducing IBGP connections in an AS.
A confederation contains sub ASs. In each sub AS, IBGP peers are fully meshed. Between sub ASs, EBGP
connections are established.