North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

RE: Weird networking issue.

  • From: ed
  • Date: Tue Jan 07 15:04:13 2003

Heh.  Tell that to my Catalyst 3548's and the E250's at the other end. ;)

Lab testing showed serious throughput issues though (expected) in
duplex-mismatched links, and large increases in runt and mutli-collision
counters.  CRC errors and FCS errors also rose in proportion to relative
link saturation in a more simplistic 6500 <->7509<-> 3548 test
environment.


 > Besides, misconfigured duplex will not cause CRC errors.
>
> C.
>
> -----Original Message-----
> From: David G. Andersen [mailto:dga@lcs.mit.edu]
> Sent: Tuesday, January 07, 2003 2:08 PM
> To: Drew Weaver
> Cc: 'nanog@merit.edu'
> Subject: Re: Weird networking issue.
>
>
>
> Rule number 1 with any ethernet:  Check to make sure you have the duplex
> and rate statically configured, and configured identically on both ends of
> the connection.
>
> I'd wager you've got half duplex set on one side, and full on the other...
>
>   -Dave
>
> On Tue, Jan 07, 2003 at 02:19:10PM -0500, Drew Weaver mooed:
> >
> > Hi, this is kind of a newbie question but this doesn't make a whole lot of
> > sense :P
> >
> > I have an etherstack hub connected to a FastEthernet port on a cisco 3660
> > router, these are the stats when I do a show int fast0/0:
> >
> > 5776 input errors, 5776 CRC, 2717 frame, 0 overrun, 0 ignored
> >
> > Whats weird is I just cleared the counters 12 minutes ago, and already
> there
> > are almost 6000 CRC errors. This connected via a standard Cat5 ethernet
> > cable, I have tried replacing the cable to noavail.
> >
> > Is this a fairly normal situation, If so that's great, but it seemed
> rather
> > ridiculous to me, and if it is not a normal situation, what would cause
> > this?
> >
> > Any ideas are appreciated.
> > Thanks,
> > -Drew Weaver
>
> --
> work: dga@lcs.mit.edu                          me:  dga@pobox.com
>       MIT Laboratory for Computer Science           http://www.angio.net/
>       I do not accept unsolicited commercial email.  Do not spam me.
>