Whether IGMP joins/leaves from a non-local network are
accepted. For example, if network 10.10.10.0/24 is defined
on circuit 1 which is connected to a physical wire for
both 10.10.10.0/24 and 10.10.11.0/24, an IGMP Join
from the 10.10.11.0/24 network may be ignored on the circuit