Autogenerated CFM and Explicitly Configured CFM

The switch simplifies CFM configuration with autogenerated CFM. With autogenerated CFM, you use the commands cfm spbm enable and cfm cmac enable and the switch creates default MD, MA, MEPs, and MIPs for SPBM B-VLANs and C-VLANs respectively.

If you choose to configure CFM explicitly, you must configure an MD, MA, MEPs, and MIPs.

Autogenerated CFM

You can use autogenerated CFM at a global level to create a MEP and a MIP at a specified level for every SPBM B-VLAN and C-VLAN on the chassis. If you use autogenerated CFM commands, you do not have to configure explicit MDs, MAs, MEPs, or MIPs, and associate them with multiple VLANs.

If you do not want to use autogenerated CFM commands, you can choose to configure explicit MDs, MAs, MEPs, and MIPs for SPBM B-VLANs. However, you cannot use both an autogenerated CFM configuration and an explicit CFM configuration together.

Note

Note

Previous explicit CFM configurations of MDs, MAs, and MEPs on SPBM B-VLANs continue to be supported. However, if you want to enable the autogenerated commands you must first remove the existing MEP and MIP on the SPBM B-VLANs. The switch only supports one type of MEP or MIP for each SPBM B-VLAN.

For information on autogenerated CFM configuration using CLI see:

For information on autogenerated CFM configuration using EDM see:

Explicitly configured CFM

If you choose to explicitly configure CFM, you must configure an MD, MA, MEPs, and MIPs. You can configure explicit CFM only on SPBM B-VLANs.

For explicit configuration information for CLI see Configuring Explicit Mode CFM.

For explicit configuration information for EDM see Configuring Explicit CFM.

Using CFM

For SPBM B-VLANs, the autogenerated MEPs and MIPs respond to l2 ping, l2 traceroute, and l2 tracetree in the same manner as the MEPs and MIPs created explicitly. For C-VLANs, the autogenerated MEPs and MIPs respond to l2 ping and l2 traceroute, but not to l2 tracetree because no multicast trees exist on C-VLANs. The CFM show commands that display MD, MA, and MEP information work for both autogenerated and explicitly configured CFM MEPs.

You can use CFM to troubleshoot networks and hosts that support the CFM protocol. After you configure CFM, CFM works in the network whether or not SPBM is in use.

You cannot use CFM to troubleshoot networks and hosts that do not support the CFM protocol, such as a customer domain that does not support CFM. Only devices that support the CFM protocol respond to l2 ping and l2 traceroute requests.