Dvmrp Interface Configuration - D-Link DES-3326SRM - Switch - Stackable Product Manual

D-Link DES-3326S Layer 3 Switch

DVMRP Interface Configuration

To configure DVMRP for an IP interface, Click the DVMRP Interface Configurations link from the IP Multicast Routing
Protocols folder:
Figure 21- 6. DVMRP Interface Configuration
Figure 21- 7. DVMRP Interface Configuration − Edit
This menu allows the Distance-Vector Multicast Routing Protocol to be configured for each IP interface defined on the switch.
The Distance Vector Multicast Routing Protocol (DVMRP) is a hop-based method of building multicast delivery trees from
multicast sources to all nodes of a network. Because the delivery trees are 'pruned' and 'shortest path', DVMRP is relatively
efficient. Because multicast group membership information is forwarded by a distance-vector algorithm, propagation is slow.
DVMRP is optimized for high delay (high latency) relatively low bandwidth networks, and can be considered as a 'best-effort'
multicasting protocol.
DVMRP resembles the Routing Information Protocol (RIP), but is extended for multicast delivery. It relies upon RIP hop
counts to calculate 'shortest paths' back to the source of a multicast message, but defines a 'route cost' to calculate which
branches of a multicast delivery tree should be 'pruned' – once the delivery tree is established.
When a sender initiates a multicast, DVMRP initially assumes that all users on the network will want to receive the multicast
message. When an adjacent router receives the message, it checks its unicast routing table to determine the interface that gives
the shortest path (lowest cost) back to the source. If the multicast was received over the shortest path, then the adjacent router
enters the information into its tables and forwards the message. If the message is not received on the shortest path back to the
source, the message is dropped.
Route cost is a relative number that is used by DVMRP to calculate which branches of a multicast delivery tree should be
'pruned'. The 'cost' is relative to other costs assigned to other DVMRP routes throughout the network.
The higher the route cost, the lower the probability that the current route will be chosen to be an active branch of the multicast
delivery tree (not 'pruned') – if there is an alternative route.
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