Configuring LSP Fragment Extension

Pre-configuration Tasks

Before configuring LSP fragment extension, create IS-IS processes.

When a new device connects to an IS-IS network, you are advised to configure LSP fragment extension and virtual systems before establishing IS-IS neighbors or importing routes. If you establish IS-IS neighbors or import routes without configuring LSP fragment extension and virtual systems, IS-IS needs to carry much information, which cannot be loaded through 256 fragments. You must then configure LSP fragment extension and virtual systems, which will take effect only after you restart the IS-IS process.

Procedure

Run system-view
The system view is displayed.
Run isis [ process-id ]
The IS-IS view is displayed.
Run lsp-fragments-extend [ [ level-1 | level-2 | level-1-2 ] | [ mode-1 | mode-2 ] ] ^*
LSP fragment extension is enabled in an IS-IS process.

By default, LSP fragment extension is disabled in an IS-IS process.

If the mode or level is not specified during the configuration of LSP fragment extension, mode-1 and level-1-2 are used by default.

If there are devices of other manufacturers on the network, LSP fragment extension must be set to mode-1. Otherwise, devices of other manufacturers cannot identify LSPs.
Run virtual-system virtual-system-id
A virtual system is configured.

By default, no virtual system is configured.

To configure a switch to generate extended LSP fragments, you must configure at least one virtual system. The ID of the virtual system must be unique in the domain.

An IS-IS process can be configured with up to 50 virtual system IDs.

Verifying the Configuration

Run the following commands to check IS-IS process statistics.

display isis statistics [ updated-lsp [ history ] ] [ level-1 | level-2 | level-1-2 ] [ process-id | vpn-instance vpn-instance-name ]
display isis process-id statistics [ [ [ updated-lsp [ history ] ] [ level-1 | level-2 | level-1-2 ] ] | [ packet ] ]