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Routing Policy Actions

An action defines what the Services Router does with the route when the route matches all the match conditions in the from and to statements for a particular term. If a term does not have from and to statements, all routes are considered to match and the actions apply to all routes.

Each term can have one or more of the following types of actions. The actions are configured under the then statement.

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

Table 68 summarizes the routing policy actions.

If you do not specify an action, one of the following results occurs:

The next term in the routing policy, if one exists, is evaluated.
If the routing policy has no more terms, the next routing policy, if one exists, is evaluated.
If there are no more terms or routing policies, the accept or reject action specified by the default policy is executed.

Table 68: Summary of Key Routing Policy Actions

Action	Description
Flow Control Actions	These actions control the flow of routing information into and out of the routing table.
accept	Accepts the route and propagates it. After a route is accepted, no other terms in the routing policy and no other routing policies are evaluated.
reject	Rejects the route and does not propagate it. After a route is rejected, no other terms in the routing policy and no other routing policies are evaluated.
next term	Skips to and evaluates the next term in the same routing policy. Any accept or reject action specified in the then statement is ignored. Any actions specified in the then statement that manipulate route characteristics are applied to the route.
next policy	Skips to and evaluates the next routing policy. Any accept or reject action specified in the then statement is ignored. Any actions specified in the then statement that manipulate route characteristics are applied to the route.
Route Manipulation Actions	These actions manipulate the route characteristics.
as-path-prepend as-path	Appends one or more autonomous system (AS) numbers at the beginning of the AS path. If you are specifying more than one AS number, include the numbers in quotation marks. The AS numbers are added after the local AS number has been added to the path. This action adds AS numbers to AS sequences only, not to AS sets. If the existing AS path begins with a confederation sequence or set, the appended AS numbers are placed within a confederation sequence. Otherwise, the appended AS numbers are placed with a nonconfederation sequence.
as-path-expand last-as count n	Extracts the last AS number in the existing AS path and appends that AS number to the beginning of the AS path n times. Replace n with a number from 1 through 32. The AS numbers are added after the local AS number has been added to the path. This action adds AS numbers to AS sequences only, not to AS sets. If the existing AS path begins with a confederation sequence or set, the appended AS numbers are placed within a confederation sequence. Otherwise, the appended AS numbers are placed with a nonconfederation sequence.
class class-name	Applies the specified class-of-service (CoS) parameters to routes installed into the routing table.
color preference color2 preference	Sets the preference value to the specified value. The color and color2 preference values can be a number from 0 through 4,294,967,295 (2³² – 1). A lower number indicates a more preferred route.
damping name	Applies the specified route-damping parameters to the route. These parameters override BGP's default damping parameters. This action is useful only in import policies.
local-preference value	Sets the BGP local preference attribute. The preference can be a number from 0 through 4,294,967,295 (2³² – 1).
metric metric metric2 metric metric3 metric metric4 metric	Sets the metric. You can specify up to four metric values, starting with metric (for the first metric value) and continuing with metric2, metric3, and metric4. For BGP routes, metric corresponds to the MED, and metric2 corresponds to the IGP metric if the BGP next hop loops through another router.
next-hop address	Sets the next hop. If you specify address as self, the next-hop address is replaced by one of the local router's addresses. The advertising protocol determines which address to use.

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