[rescue] RE:SunFastEthernet questions

Gavin Hubbard ghub005 at xtra.co.nz
Wed Sep 3 09:15:27 CDT 2003

Hi Eric

There is a reason for this. It may be counter intuitive, but setting one NIC
in a link pair to auto and the other to 100/full will result in a duplex
mismatch. In order to get 100/full, both link partners must be set to auto
or both partners must be manually set to 100/full.  No other combination
will work.

The following Cisco tech document probably explains this a lot better than I





> > I'm no physical ethernet expert, but the only explanations I
> > could come up with (constant renegotiation, actual errors, etc)
> Constant renegotiation is the best I can come up with.

I've had a system that was set to autonegotiate say the port was
running 100FDX, and the switch say the port was running 100FDX,
and still have poor throughput.  Locking both sides at 100FDX gave
me much better throughput.  I have no explanation.
Eric Dittman
dittman at dittman.net

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