Configure a Prefix List

Configure a prefix list to allow or deny specific route updates. A prefix list policy specifies route prefixes to match. After a match occurs, the system uses the route.

The prefix list contains a set of contiguous or non-contiguous routes. Reference prefix lists by name from within a routing policy.

Before you begin

To perform this procedure on a non-default VRF, you must first change the VRF instance. For information about how to use EDM for a non-default VRF, see Select and Launch a VRF Context View. All parameters might not be available in non-default VRFs.

Procedure

  1. In the navigation pane, expand Configuration > IP.
  2. Select Policy.
  3. Select the Prefix List tab.
  4. Select Insert.
  5. For Id, type an ID for the prefix list.
  6. For Prefix, type an IP address for the route.
  7. For PrefixMaskLength, type the length of the prefix mask.
  8. Configure the remaining parameters as required.
  9. Select Insert.

Prefix List Field Descriptions

Use the data in the following table to use the Prefix List tab.

Name

Description

Id

Configures the list identifier.

Prefix

Configures the IP address of the route.

PrefixMaskLen

Configures the specified length of the prefix mask.

You must enter the full 32-bit mask to exact a full match of a specific IP address, for example, if you create a policy to match on the next hop.

Name

Names a specified prefix list during the creation process or renames the specified prefix list. The name length can use from 1 to 64 characters.

MaskLenFrom

Configures the lower bound of the mask length. The default is the mask length. Lower bound and higher bound mask lengths together can define a range of networks.

MaskLenUpto

Configures the higher bound mask length. The default is the mask length. Lower bound and higher bound mask lengths together can define a range of networks.