Re: [nsp] Weird peering/routing issue

From: Nick Bauer (nick@twtelecom.net)
Date: Fri Oct 13 2000 - 16:25:30 EDT


I have seen CEF do very weird things like this on our 7507's running 12.0S.
I've seen cases where customers couldn't reach another customer on the same
router they are connected to when CEF was turned on. When we turned it off,
everything seemed normal. If your running CEF, try turning it off once. Or if
your not running it, try turning it on. I've seen as many problems fixed by
turning CEF on as I have problems fixed by turning CEF off.

And on a side note, if anyone cares to share them with me, I'd like to hear
some other stories of 7500 series routers running 12.0S code that have run
into weird issues fixed by either turning CEF on or off.

Thanks,

-Nick

Andy Waltz wrote:

> Good day,
>
> We have a customer that is peering with us using a 3640 ios 12.1.1T, our
> router is a 7507 12.0.9S. All the routing shows correctly via BGP. They
> are receiving a /19 (among the rest of the routing table) from us. Out of
> that /19 they have a /30. Basically they cannot get to any other hosts in
> the /24 (that the /30 came from). The rest of the /19 seems to work fine.
> I'm completely stumped. I'm thinking a bug in the 3640's ios, which i
> will be looking into. It is currently patched with a static route but
> obviously that isn't a permenant solution. This strange since the
> connection worked fine up to two days ago. The customer claims there have
> been no changes on their end, and the only thing i can notice that has
> happened is their connection flapped the other night (we reset bgp today
> just to make sure). One of our other customers with the same setup and
> /30 out of the same class C works fine.
>
> Obviously i could break up that aggragate i'm sending to them and send
> them the aggragate and a /24 but i'm not even confident that will work and
> obviously the other peers on that router will have to hear another /24 (as
> if there needs to be more routes in the routing table).
>
> Does anyone have any thoughts as to what might be the root cause of this
> and any possible remidies?
>
> Thanks for any assistance you can provide.
>
> andy
>
> ----
> Andy Waltz
> Network Administrator
> 513-618-1000 Fax 513-618-2000
> OneNet Communications
> andy@one.net
> ----



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