Adding a Policy Node to a Route Policy

Scenarios

A route policy can contain one or more route policy nodes, each of which consists of match conditions and policy values and can be considered as a route filter. You can add a node to a route policy if needed.

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 adding a node to the policy.
• Each node in a route policy must have a unique number.

Prerequisites

A route policy is available. You can create one by referring to create a route policy.

Procedure

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

   The node list is displayed.

3. Click Add Node in the upper left corner of the page.

   The page for adding a policy node is displayed.

4. Configure the parameters based on Table 1.

   Table 1 Parameters for adding a node

   Parameter	Description	Example Value
   Node Number	Mandatory A route policy consists of one or more nodes. When a route policy is used to filter routes, a node with a smaller number is matched first. Enter a value from 0 to 65535.	20
   Action	Mandatory Set it to Allow or Deny. If Action of a node is set to Allow and a route matches all the filtering conditions of the node, the route is allowed. If Action of a node is set to Deny and a route matches all the filtering conditions of the node, the route is denied. NOTICE: By default, routes that do not match any node in a route policy are denied. If a route policy has one or more deny nodes, you need to create a node to allow all other routes.	Allow
   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 peering connection attachments, 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: PrefVal is a Huawei-specific route attribute. 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 Peering connection attachments: 60 VPN gateway attachments: 80 Global DC gateway attachments: 100 NOTICE: Changing the PrefVal value of a route may adversely affect route selection of attachments. Submit a service ticket to evaluate the change. 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 Add Node to add more nodes if needed.
6. Click OK.

   The node list is displayed. You can view the added nodes.