Either the value '0', or the trunk number of the trunk on which a frame having a source address equal to the value of the corresponding instance has been seen. A value of '0' indicates that the source address is not associated with a trunk.
Sources for this description
Multiple manufacturers; see the original MIB MIB copies (LibreNMS/Observium Community)Netdisco MIB archive copiesNortel MIB copies (LibreNMS/Observium Community)Radware MIB copies (LibreNMS/Observium Community)