On Thu, May 14, 2009 at 12:29:17PM -0400, James Tanis wrote:
> Bill Moran wrote:
> >In response to James Tanis <jta...@mdchs.org>:
> >
> >
> >  
> >><.. snip ..>
> >>Attempting to force 1000baseTX via:
> >>
> >>ifconfig em1 media 1000baseTX mediaopt full-duplex
> >>
> >>gets me:
> >>
> >>status: no carrier
> >>
> >>After forcing the NIC to go 1000baseTX the LEDs on the backpane are both 
> >>off. I can only come to the conclusion that this is a driver issue based 
> >>on previous experience and the simple fact that the end user system is 
> >>capable of connecting at 1000baseTX. Anybody have any suggestions? I'm 
> >>hoping I'm wrong. I'd rather not do an in-place upgrade, this is a 
> >>production system and the main gateway for an entire school, when I do 
> >>not even know for sure whether this will fix the problem. It's worth it 
> >>to me though, having a 1000baseTX uplink from the switch would remove a 
> >>major bottleneck for me.
> >
> >
> >Try forcing on both ends (I assume the Procurve will allow you to do that).
> >One thing I've seen consistently is that if you force the speed/duplex on
> >one end, the other end will still try to autoneg, and will end up with
> >something stupid like 100baseT/half-duplex, or will give up and disable
> >the port.
> >  
> Ok, I just did that -- I have now attempted to force 1000baseTX on both 
> sides and on one side while the other was left auto, all three possible 
> combinations resulted in the same behavior (no carrier).
> >Also, try autoneg on both ends.  Make absolutely sure the Procurve is set
> >to autoneg.
> >  
> This was the original set up. It is also how I have it set up currently, 
> it results in 100baseTX full-duplex on both sides.
> >Replace the cable.  If the cable is marginal, autoneg will downgrade the
> >speed to ensure reliability.  Use a cable that you know will produce
> >1000baseTX because you've tested it on other systems.
> >  
> Well, I don't have any verified working cable of the appropriate length 
> so I simply switched out the cables for the main server and the backup 
> server. They are both cat6 cables crimped with cat5e modules by me. For 
> what reason (bad crimp job?) that seemed to fix the issue.
> 

This is clear indication of cabling issue. PHY of em(4) will try
to fix all cabling problem with auto MDI/MDIX/polarity correction.
If the PHY couldn't establish a 1000baseT link with link partner it
would downshift to 100baseTX as establishing a 1000baseT link was
not possible due to cabling problems(probably missing wiring).

> Thanks for the advice!
> 
> -- 
> James Tanis
> Technical Coordinator
> Computer Science Department
> Monsignor Donovan Catholic High School
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