(Optional) Configuring Routing Policies to Control VPN Route Advertisement and Acceptance

Context

The ASBRs accept all VPNv4 routes after they are configured not to filter VPNv4 routes by VPN targets. When there are many VPN routes on the network, the ASBRs are overburdened.

If only some of VPNs or sites need to communicate across ASs, you can configure a routing policy on the ASBRs to restrict the VPNv4 routes that can be accepted by the ASBRs. This reduces loads on the ASBRs.

This section describes how to configure the following filtering policies to control VPNv4 route advertisement and acceptance:

Filtering policy based VPN targets
Filtering policy based on RDs

Procedure

Run system-view
The system view is displayed.
Run either of the following command to configure a route filter.
1. To configure an extended community filter, run the ip extcommunity-filter extcomm-filter-number { permit | deny } { rt { as-number:nn | ipv4-address:nn } } &<1-16> command.
2. To configure an RD filter, run the ip rd-filter rd-filter-number { deny | permit } route-distinguisher &<1-10> command.
Run route-policy route-policy-name permit node node
A routing policy is configured.
Run either of the following command to configure an if-match clause in the configured route filter:
1. If you configured an extended community filter in 2, run the if-match extcommunity-filter { { basic-extcomm-filter-num | advanced-extcomm-filter-num } &<1-16> | basic-extcomm-filter-name } command to configure an if-match clause based on the extended community filter in the routing policy.
2. If you configured an RD filter in 2, run the if-match rd-filter rd-filter-number command to configure an if-match clause based on the RD filter in the routing policy.
Run quit
Return to the system view.
Run bgp { as-number-plain | as-number-dot }
The BGP view is displayed.
Run ipv4-family vpnv4 [ unicast ]
The BGP-VPNv4 address family is displayed.
Run peer ipv4-address route-policy route-policy-name { export | import }
The routing policy is applied to controlling the VPN IPv4 routing information.