3Com 10002211 manual Enabling and, Disabling DVMRP, Disabling IGMP, disabled, enabled

A-2 APPENDIX A: IP MULTICAST ROUTING

Enabling and	DVMRP is the simple Distance Vector Multicast Routing Protocol, similar to
Disabling DVMRP	the IP Routing Information Protocol. Multicast routers exchange distance
	vector updates that contain lists of destinations and the distance in hops to
	each destination. The routers maintain this information in a routing table.
	To run multicast routing, you must enable DVMRP, which enables it on all IP
Top-Level Menu	interfaces that have not been disabled.

system ethernet fddi tokenring bridge

➧ip ipx appletalk snmp analyzer script logout

interface		1	To enable or disable DVMRP, from the top level of the Administration
	➧dvmrp		Console, enter:
route
arp	igmp
➧multicast	interfaces		ip multicast dvmrp
	tunnel
udpHelper
routing	routeDisplay	2	Enter the slot of the switching module for which you want to enable
	cacheDisplay
icmpRouterDiscovery
rip			DVMRP.
ping
statistics			Select IP stack(s)	by slot (2,3,7,9-12all) [12]:

3	The interface prompts you to enable or disable DVMRP. The default is
	disabled.
	Slots 9-12 - Enter DVMRP mode (disabled, enabled) [disabled]:
	enabled
Enabling and	IGMP enables a router or switch to determine whether group members
Disabling IGMP	exist in a subnetwork, or “leaf,” of the Spanning Tree. It uses two search
	methods to make this determination:
■	Query mode — The router or switch with the lowest IP address in the LAN
	broadcasts a query to all other members of the subnetwork to determine
	whether they are also in the group. End-stations respond to the query with
	IGMP packets, which report the multicast group to which they belong.
■	Snooping mode — A router or switch performs dynamic multicast
	filtering based on IGMP snooping. This procedure ensures that multicast
	packets are flooded only to the appropriate ports within a routing interface.