Enabling And Disabling Dvmrp; Enabling And Disabling Igmp - 3Com LANPLEX 2500 EXTENDEDPLEX®2500 EXTENDED User Manual

10-2 C 10: A
HAPTER DMINISTERING
Enabling and
Disabling DVMRP
Top-Level Menu
system
ethernet
interface
fddi
dvmrp
route
atm
igmp
arp
bridge
interfaces
atmArpServer
ip
tunnel
multicast
ipx
routeDisplay
udpHelper
appletalk
cacheDisplay
routing
snmp
icmpRouterDiscovery
analyzer
rip
script
ping
logout
statistics
Enabling and
Disabling IGMP
IP M R
ULTICAST OUTING
DVMRP is the simple Distance Vector Multicast Routing Protocol, similar to
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 DVMRP on
all IP interfaces that have not been disabled.
To enable or disable DVMRP, from the top level of the Administration
Console, enter:
ip multicast dvmrp
The interface prompts you to enable or disable DVMRP. The default is
disabled.
Example:
dvmrp mode (enabled/disabled)[disabled]: enabled
IGMP enables a router or switch to determine whether group members
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.