H3C Technologies H3C S12500 Series Switches - Manual (Page 252)

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Configuring a large scale BGP network
In a large-scale BGP network, configuration and maintenance might become difficult due to large
numbers of BGP peers. To facilitate configuration, you can configure peer group, community, route
reflector, or confederation as needed. For information abou configuring a peer group, see " Configuring
a BGP peer group ."
Configuration prerequisites
Peering nodes are accessible to each other at the network layer.
Configuring BGP community
By default, a router does not send the community or extended community attribute to its peers or peer
groups. When the router receives a route carrying the community or extended community attribute, it
removes the attribute before advertising the route to its peers or peer groups.
This task allows you to enable a router to advertise the community or extended community attribute to its
peers, so that you can implement route filtering and control. By using this configuration together with a
routing policy, you can add and modify the community or extended community attribute of a route. For
more information about routing policy, see "Configuring routing policies."
To configure BGP community:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter BGP view or BGP-VPN
instance view.
• Enter BGP view:
bgp as-number
• Enter BGP-VPN instance view:
a. bgp as-number
b. ipv4-family vpn-instance
vpn-instance-name
Use either method.
3. Advertise the community
attribute or extended
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
Use either method.
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.