Configuring Multiprotocol Label Switching
Several technologies such as pseudowires utilize MPLS for packet transport. For information on how to configure MPLS, see the MPLS Configuration Guide, Cisco IOS Release 15.1S .
The MPLS feature is supported on the Cisco ASR 901 series routers with the following prerequisites and restrictions:
- The Cisco ASR 901 router does not necessarily support all of the commands listed in the Release 15.1(2)S documentation.
- In Cisco ASR 901 router, mpls ip is configured only on switch virtual interface (SVI). The router supports only a maximum of 60 MPLS enabled SVI interfaces.
- If port channel is configured on an MPLS core, the encapsulation ID should be the same as the bridge domain.
- The maximum number of Label Distribution Protocol (LDP) labels supported in Cisco ASR 901 router is 4000.
- MPLS byte switched counters are not supported.
- For MPLS network, the maximum number of labeled prefixes is 4000.
- For MPLS network with Fast Reroute (FRR), the maximum number of labeled prefixes is 1600.
- For MPLS network with FRR, the maximum number of VRF prefixes is 1600.
- For MPLS network with FRR, the maximum number of labeled and VRF prefixes together is 1600.
- The maximum number of prefix scalability at the global level (without MPLS) is 12000.
- The maximum number of prefix scalability for the global and VRF domain combination is 12000. Here, the VRF scale should not exceed 4000 and the overall IPv4 prefix should not exceed 12000.
- The system scalability is affected if non-MPLS (IGP’s) or MPLS scenarios exceed the prefix scalability.
MPLS labelled packet load balance over the port channel is not supported.