User`s manual

TN-5516/5518 Series Featured Functions
3-50
Network without multicast filtering
All hosts receive the multicast traffic, even if they don’t need it.
Network with multicast filtering
IGMP Group2
Group 1 Multicast Stream Group 2 Multicast Stream
IGMP Group1 IGMP Group2 IGMP Group1
Hosts only receive dedicated traffic from other hosts belonging to the same group.
Multicast Filtering and Moxa’s ToughNet switches
The TN-5500 has three ways to achieve multicast filtering: IGMP (Internet Group Management Protocol)
Snooping, GMRP (GARP Multicast Registration Protocol), and adding a static multicast MAC manually to filter
multicast traffic automatically.
IGMP (Internet Group Management Protocol)
Snooping Mode
Snooping Mode allows your switch to forward multicast packets only to the appropriate ports. The switch
snoops on exchanges between hosts and an IGMP device, such as a router, to find those ports that want to join
a multicast group, and then configures its filters accordingly.
IGMP Snooping Enhanced Mode
Snooping Enhanced Mode allows your switch to forward multicast packets to the TN-5500’s member port only.
If you disable Enhanced Mode, data streams will run to the querier port as well as the member port.