[c-nsp] Fiber issue, banging my head.

[Jared Mauch]

On Thu, Sep 06, 2007 at 02:11:03PM -0400, Drew Weaver wrote:
> Hi there.
> 
> We are trying to connect a Catalyst 6509 connected via fiber to two GSR 12000 routers.
> 
> When we connect the switch to the router(s) via G5/1 and G5/2 (on the Supervisor 720) we get input errors on the Router (the GSR side), the line goes up/up but we see:
> 
> Received 0 broadcasts, 0 runts, 0 giants, 0 throttles
>  1668 input errors, 1668 CRC, 0 frame, 0 overrun, 0 ignored
> 
> The throughput between the two pairs is also terribly slow.
> 
> We have tried different cards in the GSRs, we have tried different fiber cables.

	I'd generally recommend swapping ports, etc.. and checking different
patch panels, etc.. as you have already done.

	A few other things that may be of value:

	1) do a 'sh ip int <x/y>' to determine if the interfaces are using
CEF, etc..
	2) Make sure you don't have any odd/strange configs, such as
have you disabled proxy-arp globally on the box?  I strongly
recommend adding the following two on all your ethernet interfaces:

	no ip proxy-arp
	no ip redirects

	Those should help reduce the cpu usage of the boxes.  If you have
wonky static routes, eg: "ip route 10.0.0.0 255.0.0.0 someEthernet X/y" those
will stop working and your router cpu will come back to a sane level :)
If you tie the route to the interface, make sure you include the next-hop.

	There's a lot of dumb defaults that cisco has left in over the years
that could contribute to your issues.

	Check your interfaces, eg:

65xx#sh interfaces status
65xx#sh int gig5/1 cap
65xx#sh int gig5/1 stats

	make sure things are showing up as you expect..

	Hope this helps get you in the right direction.

	- Jared

-- 
Jared Mauch  | pgp key available via finger from jared at puck.nether.net
clue++;      | http://puck.nether.net/~jared/  My statements are only mine.