[c-nsp] Negotiation problem with Catalyst 2950 and Cisco 2821

Gert Doering gert at greenie.muc.de
Sat Dec 3 17:00:54 EST 2005


Hi,

On Sat, Dec 03, 2005 at 12:51:26PM -0700, John Neiberger wrote:
> We have the opposite philosophy. We set everything to auto. We have
> *far* more problems with hard-set switch settings. It's been my
> experience--and I have documentation at work to back this up--that
> hard setting your devices to 100/Full is the worst possible choice.

Yep.  Before long, the customer will change *something* (like "upgrade
his NIC drivers", or "replace switch with different one") and his side
will revert to auto-neg.

Fairly inevitably, it will then go to half-duplex ("my peer doesn't do 
autoneg?  Must be a dumb hub, go to HD"), and the fun begins.

We've recently changed lots of 100/full-hardwired ports to auto/auto
(leading to a-100/a-full) due to lots of port errors reported by the
switch... and voila, all errors gone.

For some combinations, especially to Cisco *routers*, manually setting
100/full is required, as the PA-FE-TX (for example) just doesn't do
autoneg.  But this is becoming the exception, not the rule, these days.

gert

-- 
USENET is *not* the non-clickable part of WWW!
                                                           //www.muc.de/~gert/
Gert Doering - Munich, Germany                             gert at greenie.muc.de
fax: +49-89-35655025                        gert at net.informatik.tu-muenchen.de


More information about the cisco-nsp mailing list