Configuring route related attributes for a VPN instance
VPN routes are controlled and advertised on a PE by using the following process:
When a VPN route learned from a CE gets redistributed into BGP, BGP associates it with a route target extended community attribute list, which is usually the export target attribute of the VPN instance associated with the CE.
The VPN instance determines which routes it can accept and redistribute according to the import-extcommunity in the route target.
The VPN instance determines how to change the route target attributes for routes to be advertised according to the export-extcommunity in the route target.
To configure route related attributes for a VPN instance:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter VPN instance view or IPv6 VPN view. |
| Configurations made in VPN instance view apply to both IPv4 VPN and IPv6 VPN. IPv6 VPN prefers the configurations in IPv6 VPN view over the configurations in VPN instance view. |
3. Configure route targets. | vpn-target vpn-target&<1-8> [ both | export-extcommunity | import-extcommunity ] | By default, no route targets are configured. |
4. Set the maximum number of active routes supported. | routing-table limit number { warn-threshold | simply-alert } | By default, the maximum number of active routes for the VPN instance is not limited. Setting the maximum number of active routes for a VPN instance can prevent the PE from storing too many routes. |
5. Apply an import routing policy. | import route-policy route-policy | By default, all routes matching the import target attribute are accepted. Make sure the routing policy already exists. Otherwise, the device does not filter received routes. For information about routing policies, see Layer 3—IP Routing Configuration Guide. |
6. Apply an export routing policy. | export route-policy route-policy | By default, routes to be advertised are not filtered. Make sure the routing policy already exists. Otherwise, the device does not filter routes to be advertised. For information about routing policies, see Layer 3—IP Routing Configuration Guide. |
7. Apply a tunnel policy to the VPN instance. | tnl-policy tunnel-policy-name | By default, only one tunnel is selected (no load balancing) in this order: LSP tunnel, and CR-LSP tunnel. The specified tunnel policy must have been created. For information about tunnel policies, see "Configuring tunnel policies." |