Configuring Igmp Snooping; Static Multicast Mac - Weidmuller IE-SW-VL08M Series User Manual

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IE-SW-VL08M Series User's Manual

VLANs that are connected to it. For networks with more than one IP router, the router with the

lowest IP address is the querier. A switch with IP address lower than the IP address of any other

IGMP queriers connected to the LAN or VLAN can become the IGMP querier.

2. When an IP host receives a query packet, it sends a report packet back that identifies the

multicast group that the end-station would like to join.

3. When the report packet arrives at a port on a switch with IGMP Snooping enabled, the switch

knows that the port should forward traffic for the multicast group, and then proceeds to forward

the packet to the router.

4. When the router receives the report packet, it registers that the LAN or VLAN requires traffic

for the multicast groups.

5. When the router forwards traffic for the multicast group to the LAN or VLAN, the switches

only forward the traffic to ports that received a report packet.

GMRP (GARP Multicast Registration Protocol)

The IE-SW-VL08M supports IEEE 802.1D-1998 GMRP (GARP Multicast Registration Protocol),

which differs from IGMP (Internet Group Management Protocol). GMRP is a MAC-based multicast

management protocol, whereas IGMP is IP-based. GMRP provides a mechanism that allows bridges

and end stations to register or de-register Group membership information dynamically. GMRP

functions similarly to GVRP, except that GMRP registers multicast addresses on ports. When a port

receives a GMRP-join message, it will register the multicast address to its database if the multicast

address is not registered, and all the multicast packets with that multicast address are able to be

forwarded from this port. When a port receives a GMRP-leave message, it will de-register the

multicast address from its database, and all the multicast packets with this multicast address are not

able to be forwarded from this port.

Static Multicast MAC

Some devices may only support multicast packets, but not support either IGMP Snooping or GMRP.

The IE-SW-VL08M supports adding multicast groups manually to enable multicast filtering.

Enabling Multicast Filtering

Use the serial console or Web interface to enable or disable IGMP Snooping and IGMP querying. If

IGMP Snooping is not enabled, then IP multicast traffic is always forwarded, flooding the network.