The LSP fast diffusion feature can speed up the diffusion of LSP. Under normal circumstances, when IS-IS receives an LSP from another router, if this LSP is newer than the corresponding LSP in the…

The LSP fast diffusion feature can speed up the diffusion of LSP. Under normal circumstances, when IS-IS receives an LSP from another router, if this LSP is newer than the corresponding LSP in the local LSDB, it updates the LSP in the LSDB and uses a timer to periodically diffuse the updated LSP in the LSDB. When a device with the LSP fast diffusion feature enabled receives one or more newer LSPs, it diffuses LSPs less than the specified number before route calculation to speed up the synchronization process of the LSDB.