[c-nsp] BFD on ME3600/ME3800/7600s

[Adam Vitkovsky]

> James Bensley
> Sent: Friday, May 27, 2016 2:28 PM
> To: cisco-nsp at puck.nether.net
> Subject: Re: [c-nsp] BFD on ME3600/ME3800/7600s
>
> In echo mode the local node sends echo packets at the specified interval of
> 50ms, the remote node loops them back in hardware (because they are UDP
> packets they shouldn't be punted to the CPU) and the local node receives
> and checks it's own echo packets.
>
Hmmm and what about the remote node?
If all the remote node does is looping packets back in HW -how does it know that the link is still operational please?
So in echo mode only one node is sending echo packets and the other node is just responsible for looping them?

I was under the impression that if you configure BFD echo mode on both ends then both ends will TX and check own packets as well as loop each other's packets.
Also I would have thought that in echo mode since each side is responsible for checking its own packets independently of the remote end then each side can also run its own timers -though I'm not sure if also in echo mode there's timers negotiation that makes sure one doesn't shoot himself in the foot.

adam









        Adam Vitkovsky
        IP Engineer

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