Configuring an IPv4 Prefix List

Procedure

1. Run system-view

   The system view is displayed.

2. Run ip ip-prefix ip-prefix-name [ index index-number ] { permit | deny } ip-address mask-length [ match-network ] [ greater-equal greater-equal-value ] [ less-equal less-equal-value ]

   An IPv4 prefix list is configured.

   The range of the mask length must meet the following requirements: mask-length <= greater-equal-value <= less-equal-value <= 32. If only greater-equal is specified, the range of the IP prefix is [greater-equal-value, 32]. If only less-equal is specified, the range of the IP prefix is [mask-length, less-equal-value].

   An IPv4 prefix list is identified by its name, and each list contains one or multiple entries. Each entry is identified by an index, and can uniquely specify a matching range in the form of a network prefix. An IPv4 prefix list named abcd is used as an example.

   During route matching, the system checks the entries identified by indexes in ascending order. If a route matches an entry, the route is no longer matched against the next entry.

   On the NetEngine 8000 F, the routes that fail to match an IPv4 prefix list are denied by default. If all entries are set to deny mode, all routes are denied by the IP prefix list. Therefore, you need to define an entry permit 0.0.0.0 0 less-equal 32 following the entries in deny mode so that other IPv4 routes will not be filtered out by the IP prefix list.

   

   If more than one IP prefix entry is defined, at least one entry needs to be set in permit mode.

3. Run commit

   The configuration is committed.