Policy Framework Configuration Guide - Juniper Networks

Junos 10.4 Policy Framework Configuration Guide
If a term does not have from and to statements, all routes are considered to match, and
the actions apply to them all. For information about the from and to statements, see
“Configuring Match Conditions in Routing Policy Terms” on page 41.
You can specify one or more actions in the then statement. There are three types of
actions:
• Flow control actions, which affect whether to accept or reject the route and whether
to evaluate the next term or routing policy.
• Actions that manipulate route characteristics.
• Trace action, which logs route matches.
NOTE: When you specify an action that manipulates the route
characteristics, the changes occur in a copy of the source route. The source
route itself does not change. The effect of the action is visible only after
the route is imported into or exported from the routing table. To view the
source route before the routing policy has been applied, use the show route
receive-protocol command. To view a route after an export policy has been
applied, use the show route advertised-protocol command.
During policy evaluation, the characteristics in the copy of the source route
always change immediately after the action is evaluated. However, the
route is not copied to the routing table or a routing protocol until the
completion of the policy evaluation is complete.
The then statement is optional. If you omit it, one of the following occurs:
• The next term in the routing policy, if one is present, is evaluated.
• If there are no more terms in the routing policy, the next routing policy, if one is present,
is evaluated.
• If there are no more terms or routing policies, the accept or reject action specified by
the default policy is taken. For more information, see “Default Routing Policies and
Actions” on page 20.
The following sections discuss the following actions:
• Configuring Flow Control Actions on page 49
• Configuring Actions That Manipulate Route Characteristics on page 49
• Configuring the Default Action in Routing Policies on page 54
• Configuring a Final Action in Routing Policies on page 56
• Logging Matches to a Routing Policy Term on page 56
• Configuring Separate Actions for Routes in Route Lists on page 57
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