Dvmrp Interface Configuration - D-Link DGS-3324SR User Manual

D-Link DGS-3324SR Layer 3 Stackable Gigabit Ethernet Switch
Robustness
Variable(1-255) <2>
Last Member Query
Interval(1-25) <1>
State <Disabled>

DVMRP Interface Configuration

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 builds it's
routing table resembling 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.
DVMRP Global Setting
To enable DVMRP globally on the Switch, click Configuration > Layer 3 IP Networking > IP Multicast
Routing Protocol > DVMRP Configuration. This will give the user access to the following screen:
Use the pull down menu, choose Enabled, and click Apply to set the DVMRP function on the Switch.
DVMRP Interface Settings
To view the DVMRP Interface Table, click Configuration > Layer 3 IP Networking > IP Multicast Routing
Protocol > DVMRP Interface Settings. This menu allows the Distance-Vector Multicast Routing Protocol
(DVMRP) to be configured for each IP interface defined on the Switch. Each IP interface configured on the
Switch is displayed in the below DVMRP Interface Configuration dialog box. To configure DVMRP for a
particular interface, click the corresponding hyperlink for that IP interface. This will open the DVMRP
Interface Configuration window:
A tuning variable to allow for subnetworks that are expected to lose a large
number of packets. A value between 1 and 255 can be entered, with larger
values being specified for subnetworks that are expected to lose larger
numbers of packets. Although a value of one (1) can be entered, this may
result in problems and is not recommended. The default setting is 2.
Specifies the maximum amount of time between group-specific query
messages, including those sent in response to leave group messages. A
value between 1 and 25. The default is 1 second.
This field can be toggled between Enabled and Disabled and enables or
disables IGMP for the IP interface. The default is Disabled.
Figure 4- 86. DVMRP Global Setting window
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