Configuring A Static Multicast Route - Foundry Networks Switch and Router Installation And Configuration Manual

Foundry Switch and Router Installation and Configuration Guide

Configuring a Static Multicast Route

Static multicast routes allow you to control the network path used by multicast traffic. Static multicast routes are
especially useful when the unicast and multicast topologies of a network are different. You can avoid the need to
make the topologies similar by instead configuring static multicast routes.
NOTE: This feature is not supported for DVMRP.
You can configure more than one static multicast route. The Layer 3 Switch always uses the most specific route
that matches a multicast source address. Thus, if you want to configure a multicast static route for a specific
multicast source and also configure another multicast static route for all other sources, you can configure two
static routes as shown in the examples below.
To add a static route for a multicast source network, use one of the following methods.
USING THE CLI
To add static routes to multicast router A (see Figure 18.8), enter commands such as the following:
PIMRouterA(config)# ip mroute 1 207.95.10.0 255.255.255.0 interface ethernet 1/2
distance 1
PIMRouterA(config)# ip mroute 2 0.0.0.0 0.0.0.0 interface ethernet 2/3 distance 1
PIMRouterA(config)# write memory
Syntax: mroute <route-num> <ip-addr> interface ethernet <portnum> | ve <num> [distance <num>]
Or
Syntax: mroute <route-num> <ip-addr> rpf_address <rpf-num>
The <route-num> parameter specifies the route number.
The <ip-addr> command specifies the PIM source for the route.
NOTE: In IP multicasting, a route is handled in terms of its source, rather than its destination.
You can use the ethernet <portnum> parameter to specify a physical port or the ve <num> parameter to specify a
virtual interface.
The distance <num> parameter sets the administrative distance for the route. When comparing multiple paths for
a route, the Layer 3 Switch prefers the path with the lower administrative distance.
NOTE: Regardless of the administrative distances, the Layer 3 Switch always prefers directly connected routes
over other routes.
The rpf_address <rpf-num> parameter specifies an RPF number.
The example above configures two static multicast routes. The first route is for a specific source network,
207.95.10.0/24. If the Layer 3 Switch receives multicast traffic for network 207.95.10.0/24, the traffic must arrive
on port 1/2. The second route is for all other multicast traffic. Traffic from multicast sources other than
207.95.10.0/24 must arrive on port 2/3.
Figure 18.8 shows an example of an IP Multicast network. The two static routes configured in the example above
apply to this network. The commands in the example above configure PIM router A to accept PIM packets from
207.95.10.0/24 when they use the path that arrives at port 1/2, and accept all other PIM packets only when they
use the path that arrives at port 2/3.
The distance parameter sets the administrative distance. This parameter is used by the software to determine the
best path for the route. Thus, to ensure that the Layer 3 Switch uses the default static route, assign a low
administrative distance value. When comparing multiple paths for a route, the Layer 3 Switch prefers the path
with the lower administrative distance.
18 - 52 December 2000