6.9. Route Policy Command Reference

This command discards changes made to a route policy.

This command enters the mode to create or edit route policies.

This command saves changes made to a route policy.

This command creates a text description that is stored in the configuration file to help identify the contents of the entity.

The no form of the command removes the string from the configuration.

This command creates a route policy AS path regular expression statement to use in route policy entries. See Regular Expressions for information.

The no form of the command deletes the AS path regular expression statement.

This command creates a route policy community list to use in route policy entries.

The community name expression form of the command extends the community name members form by allowing the community list structure to support AND, OR, and NOT operators.

When the community name members command is used, community lists operate with implicit AND support only, and all communities must match to provide a positive match, as shown in the following example, where the only routes that match include all three communities:

Using the community name expression command allows for configuration of a community expression using Boolean operators to provide flexible matching of communities. The AND operator provides functionality equivalent to the community name members command; the OR operator allows an OR match of communities; and the NOT operator allows inverted matches. If required, operators may be chained (for example, AND NOT) or enclosed within parentheses. The entire expression must be enclosed within quotation marks.

The first example above demonstrates the implementation of AND operators, which is equivalent to the members syntax (that is, “north” and “north2” are equivalent). The second example shows the OR operator, which will match a route that has target:1234:111 or target:1234:222. The third example shows the combined AND NOT operators, which will match a route that matches the regular expression for target:1234:1.1 except for target:1234.191, where “1.1” means any match of 111, 121, 131, 141, 151, 161, 171, 181, or 191. The fourth example shows the grouping of lists B and C through the use of parentheses.

The no form of the command deletes the community list or the provided community ID.

This command enables the context to configure route policies. Route policies are applied to the routing protocol.

The no form of the command deletes the route policy configuration.

This command enables the context to configure a route policy statement.

Route policy statements control the flow of routing information from a specific protocol or protocols.

The policy-statement is a logical grouping of match and action criteria. A single policy-statement can affect routing in one or more protocols and/or one or more protocols’ peers/neighbors. A single policy-statement can also affect the export of routing information.

The no form of the command deletes the policy statement.

This command triggers route policy re-evaluation.

By default, when a change is made to a policy in the config router policy-options context and then committed, the change is effective immediately. However, there may be circumstances where the changes should or must be delayed; for example, when a policy change is implemented that would affect every BGP peer on a 7705 SAR. It is more effective to control changes on a peer-by-peer basis.

If the triggered-policy command is enabled and a given peer is established, and you want the peer to remain up, then, in order for a change to a route policy to take effect, a clear command with the soft or soft-inbound option must be used. In other words, when a triggered-policy is enabled, any routine policy change or policy assignment change within the protocol will not take effect until the protocol is reset or a clear command is issued to re-evaluate route policies; for example, clear router bgp neighbor x.x.x.x soft. This keeps the peer up, and the change made to a route policy is applied only to that peer, or group of peers.

This command creates a context to configure a route damping profile to use in route policy entries.

If damping is enabled and the route policy does not specify a damping profile, the default damping profile is used. This default profile is always present and consists of the following parameters:

The no form of the command deletes the named route damping profile and uses the default damping profile.

This command configures the half-life value for the route damping profile.

The half-life value is the time, expressed in minutes, required for a route to remain stable in order for the Figure of Merit (FoM) value to be reduced by one half; for example, if the half-life value is 6 and the route remains stable for 6 min, then the new FoM value is 3. After another 3 min pass and the route remains stable, the new FoM value is 1.5.

When the FoM value falls below the reuse threshold, the route is once again considered valid and can be reused or included in route advertisements.

The no form of the command removes the half-life parameter from the damping profile and uses the value from the default profile.

This command configures the maximum suppression value for the route damping profile.

This value indicates the maximum time, expressed in minutes, that a route can remain suppressed.

The no form of the command removes the maximum suppression parameter from the damping profile and uses the value from the default profile.

This command configures the reuse value for the route damping profile. This value must be less than the suppress value.

When the Figure of Merit (FoM) value falls below the reuse threshold, the route is once again considered valid and can be reused or included in route advertisements.

The no form of the command removes the reuse parameter from the damping profile and uses the value from the default profile.

This command configures the suppression value for the route policy damping profile. This value must be greater than the reuse value

A route is suppressed when it has flapped frequently enough to increase the Figure of Merit (FoM) value so that it exceeds the suppress threshold limit. When the FoM value exceeds the suppress threshold limit, the route is removed from the route table or inclusion in advertisements.

The no form of the command removes the suppress parameter from the damping profile and uses the value from the default profile.

This command creates a context to configure a prefix list to use in route policy entries.

The no form of the command deletes the named prefix list.

This command creates a prefix entry in the route policy prefix list.

The no form of the command deletes the prefix entry from the prefix list.

This command enables the context to edit route policy entries within the route policy statement.

Multiple entries can be created using unique entries. The 7705 SAR exits the filter when the first match is found and executes the action specified. For this reason, entries must be sequenced correctly from most to least explicit.

An entry does not require matching criteria defined (in which case, everything matches) but must have an action defined in order to be considered complete. Entries without an action are considered incomplete and will be rendered inactive.

The no form of the command removes the specified entry from the route policy statement.

This command enables the context to configure policy match criteria based on a route’s source or the protocol from which the route is received.

If no condition is specified, all route sources are considered to match.

The no form of the command deletes the source match criteria for the route policy statement entry.

This command enables the context to configure export policy match criteria based on a route’s destination or the protocol into which the route is being advertised.

If no condition is specified, all route destinations are considered to match.

The to command context only applies to export policies. If it is used for an import policy, match criteria is ignored.

The no form of the command deletes export match criteria for the route policy statement entry.

This command configures an OSPF area as a route policy match criterion.

This match criterion is only used in export policies.

All OSPF routes (internal and external) are matched using this criterion if the best path for the route is by the specified area.

The no form of the command removes the OSPF area match criterion.

This command configures an AS path regular expression statement as a match criterion for the route policy entry. If no AS path criterion is specified, any AS path is considered to match. AS path regular expression statements are configured at the global route policy level (config>router>policy-options>as-path name).

The no form of the command removes the AS path regular expression statement as a match criterion.

This command configures a community list or expression as a match criterion for the route policy entry. If no community list or expression is specified, any community is considered a match.

The no form of the command removes the community list or expression match criterion.

This command specifies the external IS-IS route matching criteria for the entry.

This command specifies address families as matching conditions.

This command specifies the multicast group address prefix list containing multicast group addresses that are embedded in the join or prune packet as a filter criterion. The prefix list must be configured prior to entering this command. Prefix lists are configured in the config>router>policy-options>prefix-list context.

The no form of the command removes the criterion from the configuration.

This command specifies the router interface, specified either by name or address, as a filter criterion.

The no form of the command removes the criterion from the configuration.

This command specifies the IS-IS route level as a match criterion for the entry.

This command specifies the neighbor address as found in the source address of the actual join and prune message as a filter criterion. If no neighbor is specified, any neighbor is considered a match.

The no form of the command removes the neighbor IP match criterion from the configuration.

This command configures a BGP origin attribute as a match criterion for a route policy statement entry. If no origin attribute is specified, any BGP origin attribute is considered a match.

The no form of the command removes the BGP origin attribute match criterion.

This command configures a prefix list as a match criterion for a route policy statement entry.

If no prefix list is specified, any network prefix is considered a match.

The prefix list specifies the network prefix (this includes the prefix and length) that a specific policy entry applies to.

Up to five prefix list names can be specified.

The no form of the command removes the prefix list match criterion.

This command configures a routing protocol as a match criterion for a route policy statement entry. This command is used for both import and export policies depending on how it is used.

If no protocol criterion is specified, any protocol is considered a match.

The no form of the command removes all instances of the protocol from the match criterion.

This command specifies a multicast data source address or prefix list as a match criterion for this entry.

The no form of the command removes the criterion from the configuration.

This command adds an integer tag to the static route. These tags are then matched to control route redistribution.

The no form of the command removes the tag field match criterion.

This command configures an OSPF type metric as a match criterion in the route policy statement entry.

If no type is specified, any OSPF type is considered a match.

The no form of the command removes the OSPF type match criterion.

This command enables the context to configure actions for routes that do not match any route policy statement entries when the accept parameter is specified.

The default action clause can be set to all available action states, including accept, reject, next-entry, and next-policy. If the action states accept or reject, the policy evaluation terminates and the appropriate result is returned.

If a default action is defined and no matches occurred with the entries in the policy, the default action clause is used.

If a default action is defined and one or more matches occurred with the entries of the policy, the default action is not used.

The no form of the command deletes the default-action context for the policy statement.

This command enables the context to configure actions to take for routes matching a route policy statement entry.

This command is required and must be entered for the entry to be active.

Any route policy entry without the action command will be considered incomplete and will be inactive.

The no form of the command deletes the action context from the entry.

This command assigns a BGP AS path list to routes matching the route policy statement entry. If no AS path list is specified, the AS path attribute is not changed.

The no form of the command disables the AS path list editing action from the route policy entry.

This command prepends a BGP AS number once or numerous times to the AS path attribute of routes matching the route policy statement entry. If an AS number is not configured, the AS path is not changed.

If the optional number is specified, then the AS number is prepended as many times as indicated by the number.

The no form of the command disables the AS path prepend action from the route policy entry.

This command adds, removes, or replaces a BGP community list or expression to or from routes matching the route policy statement entry. If no community list or expression is specified, the community path attribute is not changed. Up to 28 community list or expression names can be used in one add, remove, or replace command.

The community list or expression changes the community path attribute according to the add, remove or replace keywords. If more than one of the keywords is used in a single command, first add is applied, then remove is applied. However, replace overwrites any add or remove.

The no form of the command disables the action to edit the community path attribute for the route policy entry.

This command configures a damping profile used for routes matching the route policy statement entry. If no damping criteria is specified, the default damping profile is used.

The no form of the command removes the damping profile associated with the route policy entry.

This command assigns a BGP local preference to routes matching a route policy statement entry. If no local preference is specified, the BGP configured local preference is used.

The no form of the command disables assigning a local preference in the route policy entry.

In a BGP import or export policy, this command assigns a Multi-Exit Discriminator (MED) value to routes matched by the policy statement entry. The MED value may be set to a fixed value (overriding the received value), set to the routing table cost of the route that is used to resolve the next hop of the BGP route (the metric set igp command), or modified by adding or subtracting a fixed value offset (the metric add | subtract command).

When used in a BGP export policy, the metric set igp command has the same effect as the med-out igp-cost command (see the 7705 SAR Routing Protocols Guide, “BGP Command Reference”) except that it applies only to the routes matched by the policy entry. The effect of the metric set igp command depends on the BGP policy type and the route type as summarized in Table 99.

The no form of the command removes the MED value from the route policy statement. If a MED value is configured for a BGP peer using the med-out command, that value is used (see the 7705 SAR Routing Protocols Guide, “BGP Command Reference”). If no MED is configured, no MED value is advertised.

This command assigns the specified next-hop IP address to routes matching the policy statement entry. If a next-hop IP address is not specified, the next-hop attribute is not changed.

The no form of the command disables assigning a next-hop address in the route policy entry.

This command advertises a next-hop IP address belonging to this router even if a third-party next hop is available to routes matching the policy statement entry.

The no form of the command disables advertising the next-hop-self option for the route policy entry.

This command sets the BGP origin assigned to routes exported into BGP.

If the routes are exported into protocols other than BGP, this option is ignored.

The no form of the command disables setting the BGP origin for the route policy entry.

This command assigns a route preference to routes matching the route policy statement entry.

If no preference is specified, the default route table manager (RTM) preference for the protocol is used.

The no form of the command disables setting an RTM preference in the route policy entry.

This command assigns an OSPF, IS-IS, or RIP tag to routes that do not match any entry (for default action) or that match the entry (for action). A decimal or hexadecimal value can be entered.

The no form of the command removes the tag.

This command assigns an OSPF type metric to routes that do not match any entry (for default action) or that match the entry (for action). The no form of the command disables assigning an OSPF type in the route policy entry.