Inter-AS VPLS allows a VPLS network to span multiple ASs
on an MPLS backbone network.
Usage Scenario
If multiple ASs exist on
an MPLS backbone network, the VPLS network carried over the MPLS backbone
network must be an inter-AS VPLS network. Currently, the following
inter-AS VPLS solutions are available:
- Inter-AS VPLS Option A: This solution is recommended for scenarios
where few inter-AS VPLS PWs are required. In this solution, ASBRs
must support VSIs, manage VPLS label blocks, and reserve interfaces
for inter-AS PWs. This solution poses high performance requirements
for ASBRs, but does not require inter-AS configurations to be performed
on ASBRs.
- Inter-AS VPLS Option C: This solution is recommended for scenarios
where large numbers of inter-AS VPLS PWs are required. In this solution,
ASBRs do not need to create or maintain PWs and, as a result, are
not a significant factor in network expansion.
Pre-configuration tasks
Before configuring
inter-AS VPLS, complete the following tasks:
Configure an IGP for each AS on the MPLS backbone network to
ensure IP connectivity within each AS.
Configure basic MPLS functions on the MPLS backbone network.
Configure MPLS LDP and establish LDP LSPs for each AS.
Establish an IBGP peer relationship between the PE and ASBR
in the same AS and an EBGP peer relationship between ASBRs in different
ASs. This task is specific to inter-AS VPLS Option C.
Configure VSIs on PEs and bind the VSIs to corresponding AC
interfaces.