[c-nsp] Strange RIP behaviour

[Marco Matarazzo]

Hi Michael,

> router rip
>  version 2
>  timers basic 3 10 0 10

> What strikes me is: how could it be possible to have a static selected as
> possibly down, when the connected route is (and has always be) up? I could
> ping the point to point fine from the router, no problems. The way to
> recover was simply to shut/unshut the relevant interface. Any hints what
> could be happened?

> The route should stay "possibly down" until the holddown timer
> expires, which appears to be never.

>From what I understand, a 0 as the holddown timer disables the timer, does
not set it to infinity. It simply allows alternate routes to be accepted
immediately, instead of waiting for the holddown to expire. This is also the
interpretation that Vincent C. Jones gives in his fantastic book "High
Availability Networking with Cisco".

> You could try to configure a non-zero value for the holddown timer and
watch where
> the route ends up pointing.  Otherwise debup ip rip and see what the
router is
> interpreting as the cause of marking the route possibly down.  If you
> decide to modify timer values, make sure to do it on every router in
> your routing domain.

If it happens again (as I said, it never happened in a year), I will surely
make some other tests. At the moment I had to make the customer up asap. ;)
I just have the doubt that this could be a bug, but I really don't know how
I can reproduce it!

Cheers,
]\/[arco