Can you help me. I don't know why the lsp did not switch to secondary path. I have two streams of IPv4 traffic come in the router (see the configuration below). One stream will go to to_bravo. Other will go to to_titanic.
Each stream is 6Gig. I expect the stream of to_bravo will switch to secondary path because maximum-bandwidth is only 3 Gig. But it did not. I don't know why? Thanks for your help.
The value of "maximum-bandwdith" is used as a ceiling limit when the LSP is re-signalled after the auto-bw computation. Meaning that even if the auto-bw computation yields the utilization as 4g or 6g, the LSP will be signaled with bandwidth-requirement of nor more than 3g.
You can check the same using
show mpls lsp name to_bravo extensive
If the re-signalled LSP is successful, then there would be no reason for LSP to switchover.
The mpls statistics allows the collecting of LSP statistics.
The auto-bandwidth will make your LSP resignal itself every 86400 seconds (default value but can be adjusted with adjust-interval keyword).
If the statistitics determine that your flow is 4G then the new LSP will be resignalled and reserve 4G. Another example: if the statistitics determine that your flow is 7G then the new LSP will be resignalled and reserve only 6G. This is the purpose of the keyword maximum-bandwidth 6g.
In any case a LSP is policed and traffic is dropped or redirected should the flow exceed the value of reserved bandwitdh.
Also a secondary path is just an alternative path in case the primary path cannot be up because of link or router failures. In any case it is related to flow capacity or policing.
>>> In any case a LSP is policed and traffic is dropped or redirected should the flow exceed the value of reserved bandwitdh.
I am afraid to state that the above is incorrect. The bandwidth constraint included in RSVP path T-Spec object is used only for reservation and not for data policing. You would need COS to implement the policing on the data.