Routing policy configuration task list, Defining filters, Prerequisites – H3C Technologies H3C S10500 Series Switches User Manual

Page 368: Defining an ip-prefix list, Define an ipv4 prefix list

Advertising
background image

353

Routing policy configuration task list

Complete the following tasks to configure a routing policy:

Task

Defining an IP-prefix list

Defining an AS path list

Defining a community list

Defining filters

Defining an extended community list

Creating a routing policy

Defining if-match clauses

Defining apply clauses

Configuring a routing policy

Defining a continue clause

Defining filters

Prerequisites

Before configuring this task, you must determine IP-prefix list name, matching address range, and

extcommunity list sequence number.

Defining an IP-prefix list

Define an IPv4 prefix list

Identified by name, an IPv4 prefix list can comprise multiple items. Each item specifies a prefix range to

match and is identified by an index number.
An item with a smaller index number is matched first. If one item is matched, the IP prefix list is passed,
and the routing information will not go to the next item.
Follow these steps to define an IPv4 prefix list:

To do…

Use the command…

Remarks

Enter system view

system-view

Define an IPv4 prefix list

ip ip-prefix ip-prefix-name [ index index-number ]
{ deny | permit } ip-address mask-length
[ greater-equal min-mask-length ] [ less-equal

max-mask-length ]

Required
Not defined by default.

NOTE:

If all the items are set to the deny mode, no routes can pass the IPv4 prefix list. You must define the permit
0.0.0.0 0 less-equal 32 item following multiple deny items to allow other IPv4 routing information to pass.

For example, the following configuration filters routes 10.1.0.0/16, 10.2.0.0/16, and 10.3.0.0/16, but

allows other routes to pass.

<Sysname> system-view

Advertising