Configuring IPv6 Peers

Devices can exchange BGP4+ routing information only after the IPv6 peer relationship is established among them.

Context

Because BGP4+ uses TCP connections, the IPv6 addresses for peers must be specified when you configure BGP4+. A BGP4+ peer may not be a neighboring router, and a BGP4+ peer relationship can be created by using a logical link. Using the addresses of loopback interfaces to set up BGP4+ peer relationships can improve the stability of BGP4+ connections and is recommended.

The devices in the same AS establish IBGP peer relationships, and the devices of different ASs establish EBGP peer relationships.

Procedure

Configure IBGP peers.
Perform the following steps on the routers between which an IBGP peer relationship needs to be set up:
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  The BGP view is displayed.
3. Run peer ipv6-address as-number as-number
  The address of the remote peer and the AS to which the remote peer belongs are configured.
  
  The number of the AS where the specified peer resides must be the same as that of the local AS.
  
  The IP address of the specified peer can be one of the following types:
  - IPv6 address of an interface on a directly connected peer
  - IP address of a loopback interface on a reachable peer
  - IPv6 address of a sub-interface on a directly connected peer
  - Link-local address of an interface on a directly connected peer
  If the IPv6 address used to set up a BGP4+ peer relationship is a loopback interface address, follow the procedure described in Configuring the Local Interface for the BGP4+ Connection.
4. (Optional) Run peer { ipv6-address | group-name } listen-only
  The local peer (group) is configured to accept connection requests, but not to send connection requests.
  
  After this command is run, the existing peer relationship is interrupted. The local peer will wait for a connection request from the remote peer to reestablish a peer relationship. This command enables only one peer to send connection requests, preventing a connection request conflict.
  
  This command can only be run on one of two peers. If this command is run on both peers, the connection between them cannot be reestablished.
5. (Optional) Run peer ipv6-address description description-text
  The description of the peer is configured.
  
  You can simplify network management by configuring the descriptions of peers.
6. Run ipv6-family unicast
  The IPv6 unicast address family view is displayed.
7. Run peer ipv6-address enable
  The IPv6 peer is enabled.
  
  After configuring a BGP4+ peer in the BGP view, enable the peer in the IPv6 unicast address family view.
8. Run commit
  The configuration is committed.
Configure EBGP peers.
Perform the following steps on the routers between which an EBGP peer relationship needs to be set up:
1. Run system-view
  The system view is displayed.
2. Run bgp as-number
  The BGP view is displayed.
3. Run peer ipv6-address as-number as-number
  The IPv6 address of the remote peer and the AS to which the remote peer belongs are configured.
  
  The number of the AS where the specified peer resides must be different from that of the local AS.
  
  The IP address of the specified peer can be one of the following types:
  - IPv6 address of an interface on a directly connected peer
  - IP address of a loopback interface on a reachable peer
  - IPv6 address of a sub-interface on a directly connected peer
  - Link-local address of an interface on a directly connected peer
  If the IP address used to set up a BGP4+ peer relationship is a loopback interface address, or a local-link address, follow the procedure described in Configuring the Local Interface for the BGP4+ Connection.
4. Run peer { ipv6-address | group-name } ebgp-max-hop [ hop-count ]
  The maximum number of hops is configured for establishing an EBGP connection.
  
  A direct physical link must be available between EBGP peers. If such a link does not exist, the peer ebgp-max-hop command must be used to allow EBGP peers to establish a TCP connection over multiple hops.
  
  If loopback interfaces are used to establish an EBGP peer relationship, the peer ebgp-max-hop command must be run with hop-count greater than or equal to 2; otherwise, the peer relationship cannot be established.
5. (Optional) Run peer { ipv6-address | group-name } listen-only
  The local peer (group) is configured to accept connection requests, but not to send connection requests.
  
  After this command is run, the existing peer relationship is interrupted. The local peer will wait for the connection request from the remote peer to reestablish a peer relationship. This command enables only one peer to send connection requests, preventing a connection request conflict.
  
  This command can only be run on one of two peers. If this command is run on both peers, the connection between them cannot be reestablished.
6. (Optional) Run peer ipv6-address description description-text
  The description of the peer is configured.
  
  You can simplify network management by configuring the descriptions of peers.
7. Run ipv6-family unicast
  The IPv6 unicast address family view is displayed.
8. Run peer ipv6-address enable
  The IPv6 peer is enabled.
  
  After configuring a BGP4+ peer in the BGP view, enable the peer in the IPv6 unicast address family view.
9. Run commit
  The configuration is committed.