22. Multicast Filtering
ROX™ v2.2 User Guide 207 RuggedBackbone™ RX5000
22. Multicast Filtering
ROX™ Multicast Filtering provides the following features:
• Support for up to 256 Multicast Groups (either static or dynamic).
• Ability to prioritize a Static Multicast Group via Class-of-Service.
• Industry standard support of IGMP (RFC 1112, RFC 2236) versions 1 and 2 in active and passive
roles.
• Support of IEEE 802.1Q-2005 standard GMRP (GARP Multicast Registration protocol).
• Ability to enable or disable IGMP on a per VLAN basis.
• Multicast routers may be statically configured or dynamically recognized by IGMP.
• "Routerless" IGMP operation.
ROX™ performs Multicast Filtering using the following methods:
• Static Multicast Groups.
• Internet Group Management Protocol (IGMP) snooping.
• IEEE standard GARP Multicast Registration protocol (GMRP).
ROX™ IGMP Snooping supports multicast routers using IGMP version 2 and hosts using
either IGMP version 1 or 2.
22.1. IGMP
IGMP is used by IP hosts to report their host group memberships to multicast routers. As hosts join and
leave specific multicast groups, streams of traffic are directed to or withheld from that host.
The IGMP protocol operates between multicast routers and IP hosts. When an unmanaged switch is
placed between multicast routers and their hosts, the multicast streams will be distributed to all ports.
This may introduce significant traffic onto ports that do not require it and receive no benefit from it.
RuggedCom products with IGMP Snooping enabled will act on IGMP messages sent from the router
and the host, restricting traffic streams to the appropriate LAN segments.
22.1.1. Router and Host IGMP Operation
The network shown in Figure 22.1, “IGMP Operation Example 1” provides a simple example of the use
of IGMP. One “producer” IP host (P1) is generating two IP multicast streams, M1 and M2. There are
four potential “consumers” of these streams, C1 through C4.
The multicast router discovers which host wishes to subscribe to which stream by sending general
membership queries to each of the segments.
To Next Page
Loading...
Need help?
General
