cdot1agMepIfIndex 1.3.6.1.4.1.9.9.604.1.7.1.1.2

This object is the interface index of the interface either a bridge port, or an aggregated IEEE 802.1 link within a bridge port, to which the MEP is attached. Upon a restart of the system, the system SHALL, if necessary, change the value of this variable so that it indexes the entry in the interface table with the same value of ifAlias that it indexed before the system restart. If no such entry exists, then the system SHALL set this variable to 0.