Overview of MPLS Segment Routing OAM
BGP MPLS segment routing (SR) has been deployed on the Cisco Nexus 9000 Series switches. As MPLS segment routing (SR) is deployed, a few diagnostic tools are required to help resolve the misconfigurations or failures in the segment routing network. Only Nil FEC is supported and none of the other FEC types are supported. The Nil FEC is the basic OAM FEC that is described in RFC-4379.
MPLS OAM provides two main functions for diagnostics purposes:
OAM draws the information from the FEC type to help diagnose the issues. The Nil FEC is not associated with a protocol like the other FEC types, and it is also not associated with a real FEC. For example, it is not associated with LDP etc. Logically, it only validates the data plane programming; it does not query the BGP or other routing protocols in the control plane unlike other FEC types.
To enable MPLS OAM on Cisco Nexus 9000 Series switches, use the feature mpls oam CLI command. Use the no feature mpls oam CLI command to disable MPLS OAM on Cisco Nexus 9000 Series switches.