SMC Networks SMC6724L3 manual Configuring Dvmrp, 222

CONFIGURING THE SWITCH

CLI – This example shows that multicast forwarding is enabled. The multicast routing table displays one entry for a multicast source routed by DVMRP, and another source routed via PIM.

Console#show		ip mroute	4-288
IP	Multicast	Forwarding is enabled.
IP	Multicast	Routing Table

Flags: P - Prune, F - Forwarding

(234.5.6.7, 10.1.0.0, 255.255.255.0) Owner: DVMRP

Upstream Interface: vlan2

Upstream Router: 10.1.0.0 Downstream:

(234.5.6.8, 10.1.5.19, 255.255.255.255) Owner: PIM-DM

Upstream Interface: vlan3

Upstream Router: 10.1.5.19 Downstream:

Console#

Configuring DVMRP

The Distance-Vector Multicast Routing Protocol (DVMRP) behaves somewhat similarly to RIP. A router supporting DVMRP periodically floods its attached networks to pass information about supported multicast services along to new routers and hosts. Routers that receive a DVMRP packet send a copy out to all paths (except the path back to the origin). These routers then send a prune message back to the source to stop a data stream if the router is attached to a LAN which does not want to receive traffic from a particular multicast group. However, if a host attached to this router issues an IGMP message indicating that it wants to subscribe to the concerned multicast service, this router will use DVMRP

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