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.

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3Com 10002211 manual Enabling, Disabling Dvmrp, Disabling Igmp