So far Good coverage noticed, I couldn’t find any where regarding the RSVP (Correct me if I am wrong)

  1. Would like to know about RSVP and compare RSVP vs LDP, where exactly will use RSVP? with a small topology projection will help in better understanding
  2. There are conventions like make before break (MBB) without MBB. These are applicable to LDP or RSVP? CISCO/Juniper etc., top vendors are implementing these?
  3. Please explain the FRR scenario in detail, If I want to replicate how many routers are needed? Fast reroute (FRR) convergence scenario is possible with LDP or only with RSVP?

I am looking for the above, Please help.

Hello Vamsi

Before we go into detail answering your questions, take a look at the following lessons:

You can also further research specific concepts and topics using the search utility on the site. Once you go through the lessons, we’ll be happy to more specifically answer your questions on anything that was not covered in the lessons.

I hope this has been helpful!


Hi Laz,

Thanks for the pointers, I am looking for RSVP with respect to Fast reroute (FRR) case which is major deployment currently in Network Industry.
From the links that you have provided, I couldn’t find RSVP FRR case and any information which will describe the difference between the LDP and RSVP. FYI, I have already covered LDP.
Hence all my three questions are not answered.

Again thanks for your attempt to provide the answer for my questions.


Hello Vamsi

These are quite broad topics that would be suitable to view in some future lessons. I will let @ReneMolenaar know so we can see how these can be addressed. We’ll do our best to cover them!

Thanks for pointing them out.


Hi Vamsi,

FRR isn’t implemented in RSVP only! , but also in the other known routing protocol.
The implementation itself of course are different and the commands also different.

As a little brief, the RSVP FRR on cisco is configured on the VTI of the RSVP, and also on the interface that should be placed as a secondary route that will replace the main link if it faills, those make it Fast re-route as the node routers implement a backup link in their fib regarding the specific RSVP tunnel.

In RSVP-FRR you also create the RSVP tunnel on each node router to reference teh specific RSVP tunnel to the required MPLS LABEL, and talking about configuration- this isn’t very scalable to configure and maintanance.

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