This topic describes how to add a route map to a Cloud Enterprise Network (CEN) instance. To use the route map function, you must first add a route map. After you add a route map to a CEN instance, you can filter routes and modify route attributes to manage the communication between networks attached to the CEN.
Background information
A route map is a set of conditional statements and executable statements. You can configure route maps for different regional gateways in a CEN instance. Each regional gateway can be configured with one or more route maps in the inbound and the outbound directions. The sequence of route maps of each gateway is ordered based on their priorities. When route maps are executed to evaluate a route, the system first checks whether the route matches the conditional statements of the route map with the highest priority. The route map permits or denies routes based on the configured match conditions. If a route is permitted, you can modify its attributes. For more information, see Routing policy overview.
Procedure
Log on to the CEN console.
In the left-side navigation pane, click Instances.
On the Instances page, find the target CEN instance and click Manage in the Actions column.
On the CEN page, click the Route Maps tab and then click Add Route Map.
On the Add Route Map page, configure the route map according to the following information and then click OK.
Configuration
Description
Route Map Priority
The priority of the route map. A lower value indicates a higher priority.
After configuring a route map with a specific priority value, you cannot set the same priority value for another route map that is applied in the same region and in the same direction. When route maps are executed to evaluate a route, the system first checks whether the route matches the conditional statements of the route map with the highest priority. Therefore, we recommend that you specify an appropriate priority for each route map.
Description
The description of the route map.
Region
The region where the route map is applied.
Transmit Direction
The direction in which the route map is applied.
Import to Regional Gateway: The direction in which routes are imported to the regional gateway of the CEN. For example, routes are imported to the regional gateway from an instance in the current region or another region.
Export from Regional Gateway: The direction in which routes are exported from the regional gateway of the CEN. For example, routes are exported from the regional gateway of the current region to an instance in the same region, or to the regional gateway in another region.
Match Conditions
The match conditions of the route map.
Click + Add Match Condition to add one or more match conditions. For more information, see Match conditions.
Action Policy
The action that is performed to a route if the route matches all the match conditions.
Permit: Permit the route.
After you set the Action Policy to Permit, you can add the following policy entries:
Route Preference: Set the preference for the permitted routes. Value range: 1 to 100. The default route preference is 50. A lower value indicates a higher priority.
Community: Set the community value. Two settings are supported: Add and Replace.
Prepended AS Path: An AS path is prepended when the regional gateway receives or advertises a route.
The requirements for configuring this policy entry vary depending on the application direction of the route map. The requirements are described as follows:
If the Transmit Direction of a route map is set to Import to Regional Gateway and you want to configure the Prepended AS Path as a policy entry, the match conditions must include the Source Instance IDs and the Source Region. Furthermore, you must specify the same value for the Source Region and the Region parameters.
If the Transmit Direction of a route map is set to Export from Regional Gateway and you want to configure the Prepended AS Path as a policy entry, the match conditions must include the Destination Instance IDs.
Deny: Deny the route.
If you set the Action Policy to Deny, policy entries are not supported.
Associated Priority
Optional. The priority of the next route map that is associated with the current route map. Value range: 1 to 100.
If Associated Priority is not set, the current route map is not associated with any route map that is ordered next to the current route map.
If the value is set to 1, the current route map is associated with the next route map.
If the value is set to a number other than 1, the priority of the associated route map must be lower than the priority of the current route map, that is, the value of Associated Priority must be greater than the value of Route Map Priority.
Only when the Action Policy is set to Permit for the current route map, the routes which match all the match conditions will be evaluated by the associated route map that is configured with a specific priority value.