Filtering Dvmrp Reports - Juniper JUNOSE 11.0.X MULTICAST ROUTING Configuration Manual

JUNOSe 11.0.x Multicast Routing Configuration Guide
ip dvmrp route-limit

Filtering DVMRP Reports

You can configure an interface to accept only reports with routes that appear on a
standard IP access list. You can refine the set of accepted routes further, by defining
a second access list of neighbors who can supply the specified routes.
For example, suppose you define an access list that specifies that the router accepts
only reports for the route 172.16.2.0/24. You then define a second access list that
specifies that only neighbors 192.168.1.1 and 193.168.1.1 can supply this route. If
neighbor 192.168.2.2 supplies the route, the DVMRP router rejects this report.
You can also modify the value (distance) that the router associates with a DVMRP
route when it computes the RPF interface for the source of a multicast packet. By
default, the router associates a distance of 0 with DVMRP routes; this value specifies
that the router use DVMRP, rather than a unicast routing protocol, to transport
multicast datagrams.
However, in a configuration where PIM discovers multicast routes and a unicast
routing protocol performs RPF lookups, you can increase the administrative distance
to favor the unicast protocol.
For information about defining access lists, see Configuring Routing Policy in the
JUNOSe IP Services Configuration Guide.
ip dvmrp accept-filter
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Filtering DVMRP Reports

Use to limit the number of routes that the router can advertise on each interface.
Example
host1:boston(config)#ip dvmrp route-limit 5000
Use the no version to restore the default value, 7000 routes.
See ip dvmrp route-limit.
Use to filter routes in DVMRP reports in accordance with a standard IP access
list.
Specify a standard IP access list of sources for which the interface can accept
routes.
Specify a DVMRP administrative distance to favor a unicast routing protocol.
Specify a neighbor list to restrict the neighbors from which reports for routes on
the first list can be accepted.
Example
host1:boston(config-if)#ip dvmrp accept-filter boston-list 4 neighbor-list
boston-neighbors