Dvmrp And Pim Comparison; Flood And Prune Versus Shared And Shortest Path Trees; Unicast Routes For Pim Versus Dmvrp Own Routes - Avaya 8800 Planning And Engineering

DVMRP and PIM comparison

DVMRP and PIM have some major differences in the way they operate and forward IP multicast
traffic. Choose the protocol that is better adapted to your environment. If necessary, you can
use a mix of the two protocols in different sections of the network and link them together with
the MBR feature.
DVMRP and PIM comparison navigation
•

Flood and prune versus shared and shortest path trees

•

Unicast routes for PIM versus DMVRP own routes

• Convergence and timers
• PIM versus DVMRP shutdown
Flood and prune versus shared and shortest path trees
DVMRP uses flood and prune operations whereas PIM-SM uses shared and shortest-path
trees. DVMRP is suitable for use in a dense environment where receivers are present in most
parts of the network. PIM-SM is better suited for a sparse environment where few receivers
are spread over a large area, and flooding is not efficient.
If DVMRP is used In a network where few receivers exist, much unnecessary network traffic
results, especially for those branches where no receivers exist. DVMRP also adds additional
state information about switches with no receivers.
In PIM-SM, all initial traffic must flow to the RP before reaching the destination switches. This
makes PIM-SM vulnerable to RP failure, which is why redundant RPs are used with PIM-
SM. Even with redundant RPs, the DVMRP convergence time can be faster than that of PIM,
depending on where the failure occurs.
In PIM-SM, initially, traffic must flow to the RP before dat acan flow to the receivers. This action
means that the RP can become a bottleneck, resulting in long stream initialization times. To
reduce the probability of an RP bottleneck, the switch allows immediate switching to the SPT
after the first packet is received.
Unicast routes for PIM versus DMVRP own routes
DVMRP uses its own RIPv2-based routing protocol and its own routing table. Therefore,
DVMRP can build different paths for multicast traffic than for unicast traffic. PIM-SM relies on
Planning and Engineering — Network Design
on page 196
on page 196
DVMRP and PIM comparison
on page 195
on page 195
November 2010 195