bgp-ls enable

Function

The bgp-ls enable command enables IS-IS topology advertisement to BGP.

The undo bgp-ls enable command disables IS-IS topology advertisement to BGP.

By default, IS-IS topology advertisement to BGP is disabled.

Format

bgp-ls enable [ level-1 | level-2 | level-1-2 ]

bgp-ls enable level-1 level-2-leaking-route-ignore

undo bgp-ls enable [ level-1 | level-2 | level-1-2 ]

undo bgp-ls enable level-1 level-2-leaking-route-ignore

Parameters

Parameter	Description	Value
level-1	Enables IS-IS Level-1 topology advertisement to BGP.	-
level-2	Enables IS-IS Level-2 topology advertisement to BGP.	-
level-1-2	Enables IS-IS Level-1 and Level-2 topology advertisement to BGP. If no level is specified in the command, both Level-1 and Level-2 topologies are advertised to BGP.	-
level-2-leaking-route-ignore	Ignore the routes that are leaked from Level 2 to Level 1.	-

Views

IS-IS view

Default Level

2: Configuration level

Task Name and Operations

Task Name	Operations
isis	write

Usage Guidelines

Usage Scenario

In current SDN RR+ solutions, forwarders use an IGP (OSPF or IS-IS) to collect topology information, and the IGP reports the information to the controller. This topology information collection method has the following disadvantages:

When topology information is collected within an area using an IGP, the controller must have high computing capabilities and support complicated policy control and IGP algorithms.
When topology information is collected between areas using an IGP, the controller cannot gain the complete inter-AS topology information and therefore is unable to calculate optimal E2E paths.
When inter-area topology information is collected using BGP and intra-area topology information is collected using an IGP, external interfaces will be complicated.
BGP-LS overcomes the preceding disadvantages. With BGP-LS, BGP functions as a northbound interface protocol and reports the topology information collected by an IGP to the controller. Only one device in each IGP area needs to have BGP-LS deployed, which facilitates solution deployment and improves service processing.
If IS-IS is used as the IGP and BGP-LS is required, IS-IS topology advertisement to BGP needs to be enabled using the bgp-ls enable command.
Topology information includes IPv4 node information, link information and prefix information.

Precautions

To enable each piece of link attribute information to be advertised to the controller through BGP-LS, run the advertise link attributes command or configure a global address on the interface.

Example

# Enable IS-IS Level-1 topology advertisement to BGP, and ignore the routes that are leaked from Level 2 to Level 1.

<HUAWEI> system-view
[~HUAWEI] isis
[*HUAWEI-isis-1] bgp-ls enable level-1 level-2-leaking-route-ignore

# Enable IS-IS Level-1 topology advertisement to BGP.

<HUAWEI> system-view
[~HUAWEI] isis
[*HUAWEI-isis-1] bgp-ls enable level-1