BFD for static routes

12.27.11   |  
‎12-27-2011 04:21 AM

Hi All,


i have a network scenario wherein i have two paths to another site (site 2) for redundancy purposes

SITE 1                                                                          SITE 2
Router A ---- Switch  ---------------------------switch ----- Router C
   |                                                                                   |
   |                                                                                   |
Switch                                                                         Switch
   |                                                                                   |
   |                                                                                   |
Router B ----- Switch ---------------------------------------------|

Routes A, B and C are clustered J6350s.  Router B has only static routes and the primary path to router C is through Router A.  My objective is to switch to link Y when link X fails.  Since i only have static routes, it will not be withdrawn when link X fails because the interface is still active.  

note: router A failover to router B going to Router C, however, Router B routes the packet back to router A creating a loop since the static route is not withdrawn and the qualified next hop does not become active.

If BFD can help in this scenario, can anyone provide correct BFD configuration?  what other options are available?


this is currently what i have and it doesn't work:


route {

     next-hop;    <--router A

     qualified-next-hop;   <---router C

     bfd-liveness-detection {

          minimum-interval 500;

          multiplier 3;



          minimum-receive-ttl 255;




Thank you,




Re: BFD for static routes

12.28.11   |  
‎12-28-2011 05:03 AM


Hello cyke,


 Yes, BFD should help in your case and your configuration should work (assuming you have a matching one on the remote end(s).


 What does the output of show bfd session tell you?




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Re: BFD for static routes

[ Edited ]
06.01.12   |  
‎06-01-2012 09:30 AM

Not a BFD pro by any means, but with that config, aren't you monitoring the forwarding to Router A?  If the link between router A and router B stays up, then BFD would be live right?  It's when the link between router A and C drops you want the B-C (y link) to be used.




Re: BFD for static routes

06.04.12   |  
‎06-04-2012 09:06 PM

Configuraton seems fine, are those layer 3 connectivity normal?