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Summary of Routing Policy Configuration Tasks

Table 1 describes the routing policy configuration tasks. After routing policies are configured, apply them only when using routing protocols to advertise, receive, or import routes to implement the route filtering and attribute configuration functions.

Table 1 Routing policy configuration tasks
Scenario Description Task
Configuring the filter

Routing policy filters include: ACLs, IP prefix lists, AS path filters, community filters, extended community filters, and RD filters. These routing policy filters can be applied to the if-match clauses of a routing policy and can also be used separately in specific situations.

Configuring Filters
Configuring routing policies

To reduce network burden and ensure network security, apply the routing policies with if-match clauses in the following situations:

  • Importing routes
  • Advertising and receiving routes
  • Filtering using the RT and RD attributes in the VPN
Configuring a Routing Policy
Configuring filter-policies
If you need to control receiving and advertisement of routes in each routing protocol, use filter-policies:
  • filter-policy import allows receiving only the routes that meet filtering criteria.
  • filter-policy export allows advertising only the routes that meet filtering criteria.
Configuring Filter-Policy
Configuring the valid time of a routing policy

In practical applications, when multiple cooperative configurations of a routing policy change, the routing management (RM) module immediately informs the protocols to re-apply the routing policy after a configuration is complete. If routing policies are incomplete, route flapping occurs, which results in network instability.

The processing rules for routing policy changes are as follows:

  • By default, if a routing policy changes, the RM module immediately informs the protocols to apply a new routing policy.

  • If the valid time of a routing policy is configured, the RM module does not immediately inform the protocols to process the changes when the related command configurations of the routing policy change. Instead, routing protocols wait for the configured valid time and then apply a new routing policy.

  • If the configuration of the routing policy changes again during the configured valid time, the RM module resets the timer.

To configure the valid time, run the route-policy-change notify-delay command.

Controlling the Valid Time of Routing Policies
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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