Routing
Reply
Contributor
cyke
Posts: 56
Registered: ‎06-02-2008
0

BFD for static routes

Hi All,

 

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



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



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  Since i only have static routes, it will not be withdrawn when link X fails because the interface is still active.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B going to Router C, however, Router B routes the packet back to router A creating a loop since the static route is not withdrawn and the qualified next hop does not become active.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 0.0.0.0/0 {

     next-hop 20.20.20.20;    <--router A

     qualified-next-hop 10.10.10.10;   <---router C

     bfd-liveness-detection {

          minimum-interval 500;

          multiplier 3;

          neighbor 20.20.20.20;

          local-address 20.20.20.30;

          minimum-receive-ttl 255;

     }

}

 

Thank you,

 

Cyke

Recognized Expert
erdems
Posts: 192
Registered: ‎12-30-2008
0

Re: BFD for static routes

 

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?

 

 Thanks,

 Erdem

____________________________________________
If you think your question's answered, please
mark the respective post as "Accepted Solution".

Kudos are an excellent way of showing appreciation, too.
Contributor
ed_gpc
Posts: 193
Registered: ‎09-21-2010
0

Re: BFD for static routes

[ Edited ]

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.

 

 

Contributor
jackycheung
Posts: 52
Registered: ‎02-02-2010
0

Re: BFD for static routes

Configuraton seems fine, are those layer 3 connectivity normal?

JNCIP-SP/ENT/SEC
Copyright© 1999-2013 Juniper Networks, Inc. All rights reserved.