Configuring 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

Change the VRF instance as required to configure a prefix list on a specific VRF instance.

Procedure

In the navigation pane, expand the following folders: Configuration > IP.
Click Policy.
Click the Prefix List tab.
Click Insert.
In the Id box, type an ID for the prefix list.
In the Prefix box, type an IP address for the route.
In the PrefixMaskLength box, type the length of the prefix mask.
Configure the remaining parameters as required.
Click 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.