[c-nsp] OSPF per-prefix LFA

Mohammad Khalil eng_mssk at hotmail.com
Thu May 28 07:58:36 EDT 2015


Ok , Sorry I misunderstood
So , I think combining both BFD and LFA will do the required failover time
But why changing the hello-time on both interfaces (the link between R1 and R2) will not affect ?

BR,
Mohammad

> Date: Thu, 28 May 2015 12:53:35 +0100
> From: nick at foobar.org
> To: eng_mssk at hotmail.com; cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] OSPF per-prefix LFA
> 
> This has nothing to do with OSPF virtual links.  I'm talking about the
> virtual ethernet interfaces defined in your virtual lab.
> 
> You can test out whether it's doing what I suggested by changing the
> hellotime value on the relevant interfaces.
> 
> Nick
> 
> On 28/05/2015 12:50, Mohammad Khalil wrote:
> > Hi Nick and thanks for the reply
> > All my routers are participating in area 0 , no virtual-link in place
> > I shutdown the interface connected to R2 (from CSR or R1 side)
> > 
> > BR,
> > Mohammad
> > 
> >> Date: Thu, 28 May 2015 12:36:50 +0100
> >> From: nick at foobar.org
> >> To: eng_mssk at hotmail.com; cisco-nsp at puck.nether.net
> >> Subject: Re: [c-nsp] OSPF per-prefix LFA
> >>
> >> On 28/05/2015 12:24, Mohammad Khalil wrote:
> >> > When I shutdown the interface with R2 (as I do not want to turn off the
> >> > remote interface on R2 as I cannot turn on BFD on GNS3) and I have
> >> > checked the route to 2.2.2.2 , it took about 5-6 seconds to install the
> >> > same route via the backup path (via R3)
> >>
> >> did you try this by shutting down both sides of the virtual link at the
> >> same time? The remote side will not detect carrier loss on a virtual link,
> >> so ospf failover will be detected by according to the ospf deadtime.
> >>
> >> If you handle this with bfd, the failover time should be much faster. Last
> >> time I measured this (me3600/100ms bfd), the failover time for l2vpn lsp
> >> rerouting was reliably less than 400ms. I.e. the failover for regular ip
> >> service should be a little less.
> >>
> >> Nick
> 
 		 	   		  


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