Configuring Inter-AS LDP VPLS Option C

In inter-AS LDP VPLS Option C, ASBRs do not need to maintain inter-AS LDP VPLS information or reserve interfaces for inter-AS LDP VPLS PWs. As LDP VPLS information is exchanged only between PEs, this solution requires few resources and is easy to deploy.

Procedure

Configure the capability to exchange labeled IPv4 routes.
- Perform the following steps on each PE:
  1. Run system-view
    The system view is displayed.
  2. Run bgp as-number
    The BGP view is displayed.
  3. Run peer ipv4-address label-route-capability
    The capability to exchange labeled IPv4 routes with the local ASBR is configured.
  4. Run commit
    The configuration is committed.
- Perform the following steps on each ASBR:
  1. Run system-view
    The system view is displayed.
  2. Run interface interface-type interface-number
    The view of the interface connecting to the peer ASBR is displayed.
  3. Run ip address ip-address { mask | mask-length }
    An IP address is configured for the interface.
  4. Run quit
    Return to the system view.
  5. Run mpls
    MPLS is enabled.
  6. Run quit
    Return to the system view.
  7. Run bgp as-number
    The BGP view is displayed.
  8. Run peer ipv4-address label-route-capability
    The capability to exchange labeled IPv4 routes with the local PE is configured.
  9. Run peer ipv4-address as-number as-number
    The peer ASBR is configured as an EBGP peer.
  10. Run peer ipv4-address label-route-capability
    The capability to exchange labeled IPv4 routes with the peer ASBR is configured.
    
    In inter-AS LDP VPLS Option C, an inter-AS LSP must be established and the public network routes advertised between PEs and ASBRs carry MPLS labels.
    
    An EBGP peer relationship must be established between ASBRs in different ASs for them to exchange labeled IPv4 routes.
    
    The public network routes carrying MPLS labels are advertised through MP-BGP. According to relevant standards, label mappings about routes can be piggybacked inside the BGP Update messages that are used to advertise these routes. This feature is implemented through an extended BGP attribute, which enables BGP peers to process labeled IPv4 routes.
  11. Run commit
    The configuration is committed.
Configure routing policies on each ASBR, so that an ASBR reallocates MPLS labels to the labeled IPv4 routes to be advertised to the local PE and allocates MPLS labels to the routes to be advertised to the peer ASBR.
ASBRs allocate MPLS labels to IPv4 routes based on the configured routing policies.

Perform the following steps on each ASBR:
1. Run system-view
  The system view is displayed.
2. Run route-policy policy-name1 permit node seq-number
  A routing policy applicable to the local PE is created.
3. Run if-match mpls-label
  Filtering out labeled IPv4 routes is configured as a matching rule for the routing policy.
4. Run apply mpls-label
  Allocating MPLS labels to IPv4 routes is configured as an action for the routing policy.
5. Run quit
  Return to the system view.
6. Run route-policy policy-name2 permit node seq-number
  A routing policy applicable to the peer ASBR is created.
7. Run apply mpls-label
  Allocating MPLS labels to IPv4 routes is configured as an action for the routing policy.
8. Run quit
  Return to the system view.
9. Run bgp as-number
  The BGP view is displayed.
10. Run peer ipv4-address route-policy policy-name1 export
  The routing policy applicable to the local PE is applied.
11. Run peer ipv4-address route-policy policy-name2 export
  The routing policy applicable to the peer ASBR is applied.
12. Run commit
  The configuration is committed.
Establish a remote MPLS LDP session between the PEs in different ASs, so that the PEs can exchange PW information.
- Perform the following steps on each ASBR:
  1. Run system-view
    The system view is displayed.
  2. Run bgp as-number
    The BGP view is displayed.
  3. Run network ip-address [ mask | mask-length ] [ route-policy route-policy-name ]
    The capability to advertise the local PE's loopback interface address used for BGP sessions to the peer ASBR is configured.
  4. Run quit
    Return to the system view.
  5. Run commit
    The configuration is committed.
- Perform the following steps on each PE:
  1. Run system-view
    The system view is displayed.
  2. Run mpls ldp remote-peer peer-name
    The name of the remote MPLS LDP session is specified.
  3. Run remote-ip ip-address
    The peer IP address of the remote MPLS LDP session is specified.
  4. Run commit
    The configuration is committed.
Configure LDP VPLS on each PE. For configuration details, see Configuring LDP VPLS.