[rescue] RE:SunFastEthernet questions

Eric Dittman dittman at dittman.net
Wed Sep 3 10:22:33 CDT 2003


> 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
> can:
> 
> http://www.cisco.com/warp/public/473/46.html

I guess I was a little unclear on what I had seen.  To be a little bit clearer,
I had both sides set to autonegotiate, both sides said they negotiated 100FDX,
but throughput was pretty bad.  Once I locked both sides at 100FDX, throughput
improved.

> > > 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
> _______________________________________________
> rescue list - http://www.sunhelp.org/mailman/listinfo/rescue
> 


-- 
Eric Dittman
dittman at dittman.net



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