Updated on 2024-05-20 GMT+08:00

Creating a Route Policy

Scenarios

This section describes how to create a route policy.

Notes and Constraints

  • Each node in a route policy must have a unique number.
  • Each match condition of a node must be unique. For example, a node cannot have two IP prefix lists selected as the match condition at the same time.

Procedure

  1. Log in to the management console.
  2. Click in the upper left corner and select the desired region and project.
  3. Click Service List and choose Networking > Enterprise Router.

    The Enterprise Router homepage is displayed.

  4. In the navigation pane on the left, choose Routing Control > Route Policies.

    The Route Policies page is displayed.

  5. Click Create Route Policy in the upper right corner.

    The Create Route Policy page is displayed.

  6. Configure the parameters based on Table 1.

    Table 1 Parameters for creating a route policy

    Parameter

    Description

    Example Value

    Name

    Mandatory

    Enter the name of the route policy. The name:
    • Can contain 1 to 64 characters.
    • Can contain letters, digits, underscores (_), hyphens (-), and periods (.).

    routePolicy-ab

    Description

    Optional

    Enter the description of the route policy in the text box as required.

    -

    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

  7. Click Add Node to add more nodes if needed.
  8. Click Create Now.

    The route policy list is displayed.

  9. View the route policy status.

    If the status is Normal, the route policy has been created.

Follow-Up Operations

A route policy takes effect only after you associate it with an enterprise router. For details, see Associating a Route Policy with an Enterprise Router.