[54542] in North American Network Operators' Group
RE: Weird networking issue.
daemon@ATHENA.MIT.EDU (Charles Youse)
Tue Jan 7 14:17:38 2003
From: Charles Youse <cyouse@register.com>
To: "'David G. Andersen'" <dga@lcs.mit.edu>
Cc: "'nanog@merit.edu'" <nanog@merit.edu>
Date: Tue, 7 Jan 2003 14:15:48 -0500
Errors-To: owner-nanog-outgoing@merit.edu
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By nature, a hub is half-duplex - it's a repeater.
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.
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<P><FONT SIZE=3D2>By nature, a hub is half-duplex - it's a =
repeater.</FONT>
</P>
<P><FONT SIZE=3D2>Besides, misconfigured duplex will not cause CRC =
errors.</FONT>
</P>
<P><FONT SIZE=3D2>C.</FONT>
</P>
<P><FONT SIZE=3D2>-----Original Message-----</FONT>
<BR><FONT SIZE=3D2>From: David G. Andersen [<A =
HREF=3D"mailto:dga@lcs.mit.edu">mailto:dga@lcs.mit.edu</A>]</FONT>
<BR><FONT SIZE=3D2>Sent: Tuesday, January 07, 2003 2:08 PM</FONT>
<BR><FONT SIZE=3D2>To: Drew Weaver</FONT>
<BR><FONT SIZE=3D2>Cc: 'nanog@merit.edu'</FONT>
<BR><FONT SIZE=3D2>Subject: Re: Weird networking issue.</FONT>
</P>
<BR>
<BR>
<P><FONT SIZE=3D2>Rule number 1 with any ethernet: Check to make =
sure you have the duplex</FONT>
<BR><FONT SIZE=3D2>and rate statically configured, and configured =
identically on both ends of</FONT>
<BR><FONT SIZE=3D2>the connection.</FONT>
</P>
<P><FONT SIZE=3D2>I'd wager you've got half duplex set on one side, and =
full on the other...</FONT>
</P>
<P><FONT SIZE=3D2> -Dave</FONT>
</P>
<P><FONT SIZE=3D2>On Tue, Jan 07, 2003 at 02:19:10PM -0500, Drew Weaver =
mooed:</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> Hi, this is kind of a newbie question but this =
doesn't make a whole lot of</FONT>
<BR><FONT SIZE=3D2>> sense :P</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> I have an etherstack hub connected to a =
FastEthernet port on a cisco 3660</FONT>
<BR><FONT SIZE=3D2>> router, these are the stats when I do a show =
int fast0/0:</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> 5776 input errors, 5776 CRC, 2717 frame, 0 =
overrun, 0 ignored</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> Whats weird is I just cleared the counters 12 =
minutes ago, and already there</FONT>
<BR><FONT SIZE=3D2>> are almost 6000 CRC errors. This connected via =
a standard Cat5 ethernet</FONT>
<BR><FONT SIZE=3D2>> cable, I have tried replacing the cable to =
noavail.</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> Is this a fairly normal situation, If so that's =
great, but it seemed rather</FONT>
<BR><FONT SIZE=3D2>> ridiculous to me, and if it is not a normal =
situation, what would cause</FONT>
<BR><FONT SIZE=3D2>> this?</FONT>
<BR><FONT SIZE=3D2>> </FONT>
<BR><FONT SIZE=3D2>> Any ideas are appreciated.</FONT>
<BR><FONT SIZE=3D2>> Thanks,</FONT>
<BR><FONT SIZE=3D2>> -Drew Weaver</FONT>
</P>
<P><FONT SIZE=3D2>-- </FONT>
<BR><FONT SIZE=3D2>work: =
dga@lcs.mit.edu &nb=
sp; &nb=
sp; me: dga@pobox.com</FONT>
<BR><FONT SIZE=3D2> MIT Laboratory for =
Computer =
Science <A =
HREF=3D"http://www.angio.net/" =
TARGET=3D"_blank">http://www.angio.net/</A></FONT>
<BR><FONT SIZE=3D2> I do not accept =
unsolicited commercial email. Do not spam me.</FONT>
</P>
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