The value of tmnxDot1agCfmMepMgmtIfIndex specifies, along with
tmnxDot1agCfmMepMgmtPrimaryVid, the interface index of the interface to
which the MEP is attached.
This object refers directly to IEEE8021-CFM-MIB::dot1agCfmMepIfIndex.
This object may be specified during row creation when
tmnxDot1agCfmMepMgmtType is set to either the value 'default' or
'sapPrimaryVlan'.