oversized frame warnings

David Mandala davidm@them.com
Tue Aug 18 17:33:20 1998

Hi Donald,

I should have been a more clear, I have gotten these errors from machines
when the Cisco was directly connected to the 3Com Auto hub but also when the
Cisco was directly connected to a Baynetworks 100BaseT only hub (The Cisco
4500 has a 100BaseT interface). When the Cisco is connected to the switch I
see collsion lights sometimes on the Cisco side and the only thing there is
the Cisco directly to the switch and nothing else.

I don't think its just a case of Cisco not doing autonegotiation correctly I
personally think there is something broken with the Cisco 100BaseT
implementations. Thanks for the info about Cisco's autonegotiation ability
though, I'll keep that in mind.

David Mandala

Quoting Donald Becker (becker@cesdis.gsfc.nasa.gov):
> > Quoting Liem Bahneman (roland@cobaltgroup.com):
> > > I'm using quite an old tulip.c (0.77) with 2.0.30 (for the sake of SMP
> > > stability). I've noticed that when I plug the system into a 100baseT hub,
> > > I always get:
> > > 
> > > eth1: Oversized Ethernet frame spanned multiple buffers, status 7fffceff!
> > > eth1: Oversized Ethernet frame spanned multiple buffers, status 063d81a2!
> This is usually related to a duplex mismatch.
> The newer drivers repeatedly check the negotiated duplex instead of just
> once at start-up, avoiding some problems with slow negotiation and
> powered-down switches.
> On Tue, 18 Aug 1998, David Mandala wrote:
> > Oddly enough I've seen this too, but it seemed to be coming from my Cisco
> > router. I put a 2 port switch in between my Cisco router and the 10/100
> > BaseT hub and the probme went way.
> I've gotten many reports about Cisco routers: most Cisco equipment doesn't
> do autonegotiation, or does it incorrectly.  That's why Cisco manuals
> recommend disabling autonegotiation on both ends.
> Donald Becker					  becker@cesdis.gsfc.nasa.gov
> USRA-CESDIS, Center of Excellence in Space Data and Information Sciences.
> Code 930.5, Goddard Space Flight Center,  Greenbelt, MD.  20771
> 301-286-0882	     http://cesdis.gsfc.nasa.gov/people/becker/whoiam.html