Date: Fri, 9 Oct 2009 12:40:37 -0700 From: Pyun YongHyeon <pyunyh@gmail.com> To: Ian FREISLICH <ianf@clue.co.za> Cc: current@freebsd.org Subject: Re: alc(4) link autoselect problem Message-ID: <20091009194037.GI3843@michelle.cdnetworks.com> In-Reply-To: <E1Mw82O-0006kF-PA@clue.co.za> References: <20091008170458.GC3843@michelle.cdnetworks.com> <20091007180257.GA3843@michelle.cdnetworks.com> <E1MvPZq-000Fqu-Ti@clue.co.za> <E1MvqOT-0000Oo-7F@clue.co.za> <E1Mw82O-0006kF-PA@clue.co.za>
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On Fri, Oct 09, 2009 at 07:29:08AM +0200, Ian FREISLICH wrote: > Pyun YongHyeon wrote: > > On Thu, Oct 08, 2009 at 12:38:45PM +0200, Ian FREISLICH wrote: > > > wgsw-24010# sh interfaces status ethernet g14 > > > Flow Link Back Mdix > > > Port Type Duplex Speed Neg ctrl State Pressure Mode > > > -------- ------------ ------ ----- -------- ---- ----------- -------- ---- > --- > > > g14 1G-Copper Full 100 Enabled Off Up Disabled Off > > > > > > > Hmm, does your switch have an option to enable/disable downshifting > > feature? If so, how about toggling the option? > > I'm not sure exactly what you mean. There's no configuration options > that obviously match. > Modern PHYs have ability to correct several cabling problems, for example, - pair swaps - pair skews - pair polarity - automatic MDI/MDIX - downshift to enable 10/100Mps link establishment with two pairs by downgrading the link speed to 10/100Mbps during auto-negotiation process when it can't establish 1000Mbps link. Existing cables used to connect 10/100Mbps link partners may have only two pairs. With two pairs PHYs can announce 1000Mbps capability to link partner but it can't establish the link as 1000Mbps link requires 4 pairs. Since F1 PHY seems to have above capability I just wanted to see whether disabling downshifting on link partner makes any difference. > > > > How about checking MIB statistics of controller? > > > > (sysctl dev.alc.0.stats) > > > > > > This is after a reboot, but the link was up for a short while to > > > do the above testing. rx.good_frames looks a bit high for "up 21 > > > mins". > > > > > > dev.alc.0.stats.rx.good_frames: 3348588249 > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > dev.alc.0.stats.rx.good_octets: 0 > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > > > Yeah, that looks odd, it seemed controller received a lot of good > > frames but none were meaningful packets so I guess there are link > > establishment issues. I still have no clue but if I manage to find > > more test case I will let you know. > > That number is bogus. It's currently incrementing by approximately > 33435108 per second without a cable plugged in. > Hmm, I have to test this case. Thanks. > Ian > > -- > Ian Freislich
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