ETH-CFM MPs track the SAPs, bindings and facility independently. Therefore, when an MP is configured on a SAP which is not operationally up because of MC-LAG ETH-CFM defect, conditions are raised for what could be considered normal conditions. Figure: Independent processing UP MEP example shows the default behavior for a point-to-point service without regard for MC-LAG. In the case below, the two up MEPs operating at level 4 on the affected SAPs set the Interface-Status-TLV bit in the ETH-CC header to represent the isDown condition, assuming ETH-CC is executing between the peer MEPs. This is the correct action based on the ETH-CFM perspective, SAPs are operationally down.
A similar condition exists if down MEPs are configured on the SAPs that are operationally down. Figure: Independent processing down MEP example shows how the same service configured with down MEPs would generate AIS, if enabled, toward the remote client at the configured client-meg-level, in the reverse direction of the MEP. This is also the correct behavior from the perspective ETH-CFM.
