Why CSPF is required for Fast Failover (FRR, Link/Node Protection)??

[aeroplane]

Hi Experts

Whey CSPF (Traffic Engineering Database) is required for MPLS Fast Failover in MPLS? Because as I believe it is required for MPLS traffic engineering (that is link colouring, bandwidth reservation etc).

Thanks for the reply

[emusamu]

Hi Aeroplane,

The detour bypass lsp that is to be used in case of link failure should be adequate to accommodate all TE specs needed by the protected lsp.

BR

[Kashif-rana · Accepted solution]

Hi

The detour (fast reroute) inherits the link colouring from the protected LSP although bypass LSP (link/node protection) does not. But you can manually specify the link colouring/bandwidth for the detour and bypass LSP. Since link colouring and bandwidth reversation etc requires the CSPF thats why FRR, Link/Node protection needs the CSPF.

HTH

[aeroplane]

Thanks for both. How we can specify the contrainsts for detours?