The value of tmnxIPMafMatchSrcIpAddrType specifies the type of
IP address stored in the object tmnxIPMafMatchSrcIpAddr.
If the value of tmnxGenMafType indicates 'ipv4' the only allowed
values for this object are 'unknown' or 'ipv4'.
If the value of tmnxGenMafType indicates 'ipv6' the only allowed
values for this object are 'unknown' or 'ipv6'.