[c-nsp] MPLS Q's

[Annu Roopa]

Hi,
 
Hopefully one of u will be able to answer my Q's which maybe more out of ignorance and/or limited experience.Any pointers and URls will surely help.
 
1. What exactly is the difference between "Explicit Null" and "Implicit Null". Does Cisco implementation use Explicit Null at all ?
 
Some MPLS-TE Qs:

Mainly I am trying to understand the configuration options and behavior when I specify a path-option under TE tunnel interface. While creating 'ip explicit-path' the following options are available: Strict and loose

While specifying the path-option under tunnel interface the following options are available: explicit and dynamic, both can be specified with lockdown option

Now my questions are:

A. Let us say I specified two path-options, one is explicit and has higher preference and the other is dynamic and has lower preference. Initially let us say that the explicit path was not available and the TE tunnel was setup using the dynamic path option. After sometime if the explicit path becomes available, will the Head end node tear down the already established dynamic path and recreate the tunnel using the explicit path? 

B. The same question as A but the dynamic option specified as 'lockdown'. In this case what will be the behavior when the explicit path becomes available?

C. If I understand correctly the 'lockdown' option means that the LSP is not a candidate for re-optimization. By default it seems like all path options are 'candidates for re-optimization', is there any reason for this? Meaning, why should an already setup LSP be torn down (in case better path is available), will it not affect data traffic flow?

Thanks for ur time and replies in advance.

Annu.

 


		
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