Modifying a Policy Node in a Route Policy

Scenarios

This section describes how to modify a node in a route policy.

Notes and Constraints

• Route policies change the path through which network traffic passes. If a route policy has already been associated with an enterprise router, evaluate the impact on services before modifying its nodes.
• Changing a route policy will also change the associated routes. To reduce the impact on network performance, a route policy can only be changed once within 40 seconds.

Procedure

1. Go to the Route Policies page.
2. Click the name of the target route policy.

   The node list is displayed.

3. Locate the row that contains the node you want to modify and click Modify in the Operation column.

   The page for modifying a node is displayed.

4. Configure the parameters based on Table 1.

   Table 1 Parameters for modifying a node

   Parameter	Description	Example Value
   Node Number	Cannot be modified.	-
   Action	Cannot be modified.	-
   Match Condition	Mandatory Select match conditions. You can select a route type, prefix list, or AS_Path list. Route type Static: Manually configured routes Custom routes and propagated routes of VPC attachments in enterprise router route tables are static routes. BGP: Routes learned through BGP Direct Connect virtual gateways communicate with enterprise routers using BGP so the routes of virtual gateway attachments propagated to enterprise router route tables are BGP routes. Also, the routes of VPN gateway attachments and global DC gateway attachments propagated to enterprise router route tables are BGP routes. An IP prefix list contains prefix rules for route filtering. You can define IP prefixes and netmasks in prefix rules to match the destination addresses or next hops of routes. For more information, see IP Prefix List Overview. An AS_Path list is a collection of filters that are used to filter BGP routes based on AS_Path attributes contained in BGP routes. AS_Path attributes record the number of each AS that BGP routes pass through from the source to the destination in distance-vector order. For more information, see AS_Path List Overview.	Route type: BGP IP prefix list: prefixFilter-ab AS_Path list: asPathFilter-ab
   Policy Value	Optional You can configure policy values for a route as required if you set Action to Allow. Each node can have up to two policy values. You can click Add Policy Value to add policy values. PrefVal: A larger PrefVal value indicates a higher route priority. You can change the PrefVal value of a route by changing the PrefVal value in the route policy. A PrefVal value must be an integer. The default PrefVal values of routes for different types of enterprise router attachments are as follows: Virtual gateway attachments: 100 VPN gateway attachments: 80 Global DC gateway attachments: 100 AS_Path attributes record the number of each AS that BGP routes pass through from the source to the destination in distance-vector order. You can add, replace, or delete AS_Path policy values. Add a policy value to the left of AS_Path. Replace the original policy value of AS_Path. Delete the specified policy value of AS_Path. AS_Path policy values must meet the following requirements: Each value is an integer in the format of x or x.y. (x: 1 to 65535; y: 0 to 65535). A maximum of 10 values can be entered at a time. Each value must be unique.	PrefVal: 20 AS_Path: 2000 10.2 3.7 500

5. Click OK.

   The node list is displayed. You can view the modified node.