import-route isis level-1 into level-2 (IS-IS topology view)

Format

import-route isis level-1 into level-2 [ tag tag | filter-policy { acl-number | acl-name acl-name | ip-prefix ip-prefix-name | route-policy route-policy-name | route-filter route-filter-name } | direct allow-filter-policy ] ^*

undo import-route isis level-1 into level-2

Parameters

Parameter	Description	Value
tag tag	Specifies the administrative tag assigned to the imported routes.	The value is an integer ranging from 1 to 4294967295.
filter-policy	Indicates a filtering policy to filter imported routes. Only the IS-IS Level-1 area routes that match the filtering policy can leak to a Level-2 area.	-
acl-number	Specifies the number of a basic ACL. Only the IS-IS Level-1 area routes that match the ACL rule can leak to a Level-2 area.	The value is an integer ranging from 2000 to 2999.
acl-name acl-name	Specifies the name of a named basic ACL. Only the IS-IS Level-1 area routes that match the ACL rule can leak to a Level-2 area.	The value is a string of 1 to 64 case-sensitive characters without spaces. The value must start with a letter (a to z or A to Z, case sensitive).
ip-prefix ip-prefix-name	Specifies the name of an IP prefix list. Only the IS-IS Level-1 area routes that match the IP prefix list can leak to a Level-2 area.	The name is a string of 1 to 169 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
route-policy route-policy-name	Specifies the name of a route-policy. Only the IS-IS Level-1 area routes that match the route-policy can leak to a Level-2 area.	The name is a string of 1 to 200 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string.
route-filter route-filter-name	Specifies the name of a route filter policy. The policy is used to filter the imported routes so that only some of the routes of other routing domains can be imported.	The value is a string of 1 to 200 case-sensitive characters, spaces not supported. If parameters are included in the referenced route-filter, specify values for them in the format of (var1, var2, ...var8) behind the route-filter name. A maximum of eight parameters can be specified, and each value ranges from 1 to 200 characters.
direct	Imports direct routes.	-
allow-filter-policy	Indicates a filtering policy to filter the direct routes. If the parameter is configured, only the IS-IS Level-1 area direct routes that match the filtering policy can leak to a Level-2 area. If the parameter is not configured, all Level-1 area direct routes will leak to a Level-2 area.	-

Views

IS-IS topology view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

When multiple Level-1-2 devices in an IS-IS Level-1 area are connected to a Level-2 area, information about all the routes except the default route in the Level-1 area leak to the Level-2 area. The routes in the Level-1 area destined for one device in the Level-2 area may be forwarded by the same Level-1-2 device, causing traffic imbalance.

You can run the import-route isis level-1 into level-2 command on one Level-1-2 device to enable some Level-1 routes to leak to the Level-2 area and run the command on other Level-1-2 devices to enable the rest Level-1 routes to leak to the Level-2 area. Then, traffic that is sent from the Level-2 area and destined for different network segments in the Level-1 area will be forwarded to different Level-1-2 routers.

Prerequisites

An IS-IS process has been created using the isis command.

Configuration Impact

After the undo import-route isis level-1 into level-2 command is run, the IS-IS backbone area cannot obtain the routes in the Level-1 area, causing area disconnection.

Precautions

In the route-policy specified in this command, if-match clauses can be configured to set matching rules, but apply clauses cannot be configured to set route attributes.

Example

# Use the filter-policy named 2000 to control leaking of the IS-IS routes in the topology named red from a Level-1 area to a Level-2 area.

<HUAWEI> system-view
[~HUAWEI] acl 2000
[*HUAWEI-acl4-basic-2000] quit
[*HUAWEI] ip topology red
[*HUAWEI] isis 1
[*HUAWEI-isis-1] cost-style wide
[*HUAWEI-isis-1] topology red topology-id 10
[*HUAWEI-isis-1-topology-red] import-route isis level-1 into level-2 filter-policy 2000