(Revised 4-9-2013) NT24k Managed Industrial Ethernet Switch User Manual & Installation Guide Page 55 of 132
IGMP – RFilter Ports
The ‘rfilter’ (
Router Multicast Data Filter
) function allows you to choose whether or not DATA frames
with KNOWN group multicast addresses are sent to the ‘router’ ports (links to other switches). Control
packets (Join, Leave) will be sent to the router(s) regardless of this setting. “KNOWN” is known from
dynamic IGMP Snooping operations. If IGMP is enabled and a port is a 'router port', then RFilter enabled
stops IGMP group data from egressing on the port unless a join to that specific IGMP group has come into
the port. IGMP controls (Join, Leave, Query) are still sent.
The factory default is that the Router Multicast Data Filter is enabled for all ports, so any router ports do
NOT get DATA frames with KNOWN multicast destination addresses unless a join to a specific multicast
address has been received on that port.
Joins override an rfilter.
If rfilter is disabled, router ports do get DATA frames with KNOWN multicast destination addresses
Rfilter can be set for individual ports: any, all, or none. For each port, rfilter will have an impact only if that
port is manually or dynamically chosen as a router port.
Default configuration:
