Policy Framework Configuration Guide - Juniper Networks

Junos 10.4 Policy Framework Configuration Guide
Configuring Prefix Lists for Use in Routing Policy Match Conditions
A prefix list is a named list of IP addresses. You can specify an exact match with incoming
routes and apply a common action to all matching prefixes in the list.
NOTE: Because the configuration of prefix lists includes setting up prefixes
and prefix lengths, we strongly recommend that you have a thorough
understanding of IP addressing, including supernetting, before proceeding
with the configuration.
A prefix list functions like a route list that contains multiple instances of the exact match
type only. The differences between these two extended match conditions are summarized
in Table 19 on page 116.
Table 19: Prefix List and Route List Differences
Feature
Prefix List
Route Lists
Action
Can specify action in a then
statement only. These actions are
applied to all prefixes that match
the term.
Can specify action that is applied to
a particular prefix in a route-filter
match condition in a from statement,
or to all prefixes in the list using a
then statement.
For information about configuring route lists, see “Configuring Route Lists for Use in
Routing Policy Match Conditions” on page 119.
This section includes the following information:
• Configuring Prefix Lists on page 116
• How Prefix Lists Are Evaluated in Routing Policy Match Conditions on page 118
• Configuring Prefix List Filters on page 118
Configuring Prefix Lists
You can create a named prefix list and include it in a routing policy with the prefix-list
match condition (described in “Configuring Match Conditions in Routing Policy Terms”
on page 41).
To define a prefix list, include the prefix-list statement:
prefix-list prefix-list-name {
apply-path path;
ip-addresses;
}
You can include this statement at the following hierarchy levels:
• [edit policy-options]
• [edit logical-systems logical-system-name policy-options]
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