Marvell chipsets on 8-CURRENT and XP x64 won't talk with one another

[Bill Moran]

Mike Silbersack <silby at silby.com> wrote:
>
> 
> On Fri, 19 Oct 2007, Garrett Cooper wrote:
> 
> >> Just to clarify, how are the two hooked together?  Is it over gigabit 
> >> switch, a 10mbps hub, or directly cabled together?
> >> 
> >> -Mike
> >
> >   Sure. They're both connected over a gigabit switch, but the Windows 
> > driver's kind of sketchy because it keeps on switching between 100MBit and 
> > 1GBit. I haven't really paid that much attention to what speed the FreeBSD 
> > msk driver is registering at.
> > -Garrett
> 
> Ah ha!
> 
> I had the flopping between 100mbps and 1gbps problem with some Intel cards 
> once - some of the machines in the lab were fine, others kept switching 
> back and forth.  We eventually narrowed it down to the cables we had 
> hand-made; some of them just weren't up to snuff, and the NIC apparently 
> decided that it had to go back down to 100.
> 
> I think you should switch your gigabit switch out for a 100mbps switch and 
> see if the network becomes more reliable.

Better would be to:
a) Fix or replace the faulty wiring.  Just because it _seems_ to be OK
   at 100 doesn't mean it is.  If it's unable to work reliably at a
   speed it should work at, you need to fix that.
b) Force the speed/duplex on both ends.  One of the ugliest networking
   problems I've seen is when the two ends negotiate different speeds
   or duplexes.  It amazes me how few people are familiar with this
   problem and how to diagnose/fix it.

-- 
Bill Moran
Collaborative Fusion Inc.

wmoran at collaborativefusion.com
Phone: 412-422-3463x4023