The filter-policy export command configures a filtering policy to allow IS-IS to filter the imported routes to be advertised.
The undo filter-policy export command disables the filtering function.
By default, the filtering function is disabled.
filter-policy { acl-number | ip-prefix ip-prefix-name | route-policy route-policy-name } export [ direct | static | rip process-id | bgp | unr | ospf process-id | isis process-id ]
undo filter-policy export [ direct | static | rip process-id | bgp | unr | ospf process-id | isis process-id ]
undo filter-policy { acl-number | ip-prefix ip-prefix-name | route-policy route-policy-name } export [ direct | static | rip process-id | bgp | unr | ospf process-id | isis process-id ]
| Parameter | Description | Value |
|---|---|---|
| acl-number | Specifies the number of a basic ACL. | The value is an integer ranging from 2000 to 2999. |
| ip-prefix ip-prefix-name | Specifies the name of the IP prefix-list. | 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. |
| acl6-number | Specifies the number of a basic ACL6. | The value is an integer ranging from 2000 to 2999. |
| ipv6-prefix ipv6-prefix-name | Specifies the name of an IPv6 prefix list. | 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 the routing policy to filter the routes based on tag and other parameters of the protocol. | The name is a string of 1 to 40 case-sensitive characters, with spaces not supported. When double quotation marks are used around the string, spaces are allowed in the string. |
| direct | Indicates the imported direct routes that need to be filtered when the routes are advertised. | - |
| static | Indicates the imported static routes that need to be filtered when the routes are advertised. | - |
| rip | Indicates the imported RIP routes that need to be filtered when the routes are advertised. | - |
| process-id | Indicates the process ID of rip, ospf, ripng, ospfv3, or other isis process. | The value is an integer ranging from 1 to 65535. |
| bgp | Indicates the imported BGP routes that need to be filtered when the routes are advertised. | - |
| unr | Specifies UNR routes. | - |
| ospf | Indicates the imported OSPF routes that need to be filtered when the routes are advertised. | - |
| isis | Indicates the imported IS-IS routes that need to be filtered when the routes are advertised. | - |
| ospfv3 | Indicates the imported OSPFv3 routes that need to be filtered when the routes are advertised. | - |
| ripng | Indicates the imported RIPng routes that need to be filtered when the routes are advertised. | - |
Usage Scenario
When IS-IS and other routing protocols are running on the network, and a boundary router in the IS-IS domain has imported routes of other routing protocols, the boundary router will advertise all the imported routes to its IS-IS neighbors by default.
When the routes that meet certain conditions need to be advertised, you can run this command to configure filtering rules. In this manner, only the routes that meet the filtering rules can be advertised.
Prerequisites
The import-route command has been run to import routes of other routing protocols.
Configuration Impact
Running the filter-policy export command does not affect the routes on the local device, but only advertises specific imported routes to IS-IS neighbors.
Precautions
The filter-policy { acl-number | ip-prefix ip-prefix-name | route-policy route-policy-name } export [ direct | static | rip process-id | bgp | ospf process-id | isis process-id ] command is used to configure the route filtering function in an IPv4 base topology or an IPv4 topology instance.
The filter-policy { acl6-number | acl6-name acl6-name | ipv6-prefix ipv6-prefix-name | route-policy route-policy-name } export [ direct | static | ospfv3 process-id | ripng process-id | isis process-id | bgp ] command is used to configure the route filtering function in an IPv6 topology instance.
The ipv6 filter-policy export command is used to configure route filtering in an IPv6 base topology.
Creating an ACL before it is referenced is recommended. If a nonexistent ACL is referenced using the command, all external routes of the specified routing domain that are imported by IS-IS are advertised to the specified neighbor.
Creating an IP prefix list or route-policy before it is referenced is recommended. By default, nonexistent IP prefix lists or route-policies cannot be referenced using the command. If the route-policy nonexistent-config-check disable command is run in the system view and a nonexistent IP prefix list or route-policy is referenced using the current command, all external routes of the specified routing domain that are imported by IS-IS are advertised to the specified neighbor.