(Optional) Configuring a Router ID for a BGP-VPN Instance IPv4 Address Family

You can configure different router IDs for BGP VPN instance IPv4 address families on the same device.

Context

By default, no router ID is configured for a BGP-VPN instance IPv4 address family, and the BGP router ID is used. As a result, different BGP-VPN instance IPv4 address families on the same device have the same router ID. In some cases, different router IDs need to be configured for different BGP-VPN instance IPv4 address families. For example, BGP peer relationships need to be established between different BGP-VPN instance IPv4 address families on the same PE.

Two methods are available for configuring a router ID for a BGP-VPN instance IPv4 address family. Choose either of the following methods as required:

Configure router IDs for all BGP-VPN instance IPv4 address families.
Configure a router ID for a specified BGP-VPN instance IPv4 address family.

The router ID configured in the BGP-VPN instance IPv4 address family view takes precedence over the router ID configured in the BGP view.

If a BGP session has been established in a BGP-VPN instance IPv4 address family, changing or deleting the configured router ID resets the BGP session.

Procedure

Configure router IDs for all BGP-VPN instance IPv4 address families.
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  The BGP view is displayed.
3. Run router-id { ipv4-address | vpn-instance auto-select }
  Automatic router ID selection is configured for all BGP-VPN instance IPv4 address families.
  
  In the BGP view, the router-id vpn-instance auto-select command takes precedence over the router-id ipv4-address command.
  Rules for automatically selecting a router ID for a BGP VPN instance IPv4 address family are as follows:
  - If the loopback interfaces configured with IP addresses are bound to the VPN instance enabled with the IPv4 address family, the highest IP address among the IP addresses of the loopback interfaces is selected as the router ID.
  - If no loopback interfaces configured with IP addresses are bound to the VPN instance enabled with the IPv4 address family, the highest IP address among the IP addresses of other interfaces bound to the VPN instance is selected as the router ID, regardless of whether the interface is Up or Down.
4. Run commit
  The configuration is committed.
Configure a router ID for a specified BGP-VPN instance IPv4 address family.
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  The BGP view is displayed.
3. Run ipv4-family vpn-instance vpn-instance-name
  The BGP-VPN instance IPv4 address family view is displayed.
4. Run router-id { ipv4-address | auto-select }
  A router ID or automatic route ID selection is configured for the current BGP-VPN instance IPv4 address family.
5. Run commit
  The configuration is committed.