Inbound Route Filters - Nokia IPSO 4.0 Reference Manual

Inbound Route Filters

Inbound route filters allow a network administrator to restrict or constrain the set of routes
accepted by a given routing protocol. The filters let an operator include or exclude ranges of
prefixes from the routes that are accepted into RIP, IGRP, OSPF and BGP. These filters are
configured in the same way as the filters for route redistribution.
Note
You can also use route maps to specify inbound route filters. You can define route maps only
using CLI commands. For information on route maps, see
the CLI Reference Guide.
An administrator can specify two possible actions for each prefix—accept the address into the
routing protocol (with a specified rank) or exclude the prefix.
You can specify the type of prefix matching done for filter entries in the following ways:
Routes that exactly match the given prefix; that is, have the same network portion and prefix
length.
Routes that match more specific prefixes but do not include the given prefix. For example, if
the filter is 10/8, then any network 10 route with a prefix length greater than 8 matches, but
those with a prefix length of 8 do not match.
Routes that match more specific prefixes and include the given prefix. For example, if the
filter is 10/8, then any network 10 route with a prefix length greater than or equal to 8
matches.
Routes that match a given prefix with a prefix length between a given range of prefix
lengths. For example, the filter could specify that it match any route in network 10 with a
prefix length between 8 and 16.
To configure IGP inbound filters
1. Click Inbound Route Filters under Configuration > Routing in the tree view.
2. Click Filter Inbound RIP Routes.
Note
All other IGPs are configured in exactly the same way.
3. In the All Routes Action field, click either Accept or Restrict.
If you select accept, routes can be rejected individually by entering their IP address and
mask length in the appropriate fields. Similarly, if you select
accepted individually by entering their IP address and mask length in the appropriate fields.
4. If you set All Routes to accept and click Apply, the Rank field is displayed.
In the Rank field you can specify the rank to a value that all routes should have. The range of
values is 1 to 255.
Nokia Network Voyager for IPSO 4.0 Reference Guide
"Route Maps" on page 353 and
, routes can be
RESTRICT
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