On Wed, 2008-05-28 at 16:02 -0700, Jeff Haran wrote: > > -----Original Message----- > > From: linux-net-owner@xxxxxxxxxxxxxxx > > [mailto:linux-net-owner@xxxxxxxxxxxxxxx] On Behalf Of Matt Zagrabelny > > Sent: Wednesday, May 28, 2008 2:45 PM > > To: linux-net@xxxxxxxxxxxxxxx > > Subject: connecting two hosts with crossover cable and autonegotiation > > > > Greetings, > > > > I am working on creating a GNU/Linux HA cluster and have a (non-gig) > > crossover cable connecting eth2 on both nodes. The question I have is > > how do cards like this auto-negotiate. They are negotiating to 10/half > > whereas I would expect them to negotiate to 100/full. > > > > Some details: > > > > Debian GNU/Linux Etch > > # uname -a > > Linux squash 2.6.18-6-686 #1 SMP Thu May 8 07:34:27 UTC 2008 i686 > > GNU/Linux > > > > > > The NICs on both nodes are 3Com 10/100: > > > > Ethernet controller: 3Com Corporation 3c905C-TX/TX-M > > [Tornado] (rev 6c) > > Subsystem: 3Com Corporation 3C905C-TX Fast Etherlink for PC Management > > NIC > > > > Here are the results of 'mii-tool'. > > > > node1# mii-tool -v eth2 > > eth2: no autonegotiation, 10baseT-HD, link ok > > product info: vendor 00:10:18, model 23 rev 4 > > basic mode: autonegotiation enabled > > basic status: autonegotiation complete, link ok > > capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD > > advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD > > flow-control > > link partner: 10baseT-HD > > > > node2# mii-tool -v eth2 > > eth2: link ok > > product info: vendor 00:10:18, model 23 rev 4 > > basic mode: autonegotiation enabled > > basic status: link ok > > capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD > > advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD > > flow-control > > > > > > Here are the results of 'mii-diag'. > > > > node1# mii-diag eth2 > > Basic registers of MII PHY #24: 3000 782d 0040 6174 05e1 0021 0000 > > 0000. > > Basic mode control register 0x3000: Auto-negotiation enabled. > > You have link beat, and everything is working OK. > > Your link partner is generating 10baseT link beat (no > > autonegotiation). > > End of basic transceiver information. > > > > node2# mii-diag eth2 > > Basic registers of MII PHY #24: 3000 780d 0040 6174 05e1 0000 0000 > > 0000. > > Basic mode control register 0x3000: Auto-negotiation enabled. > > You have link beat, and everything is working OK. > > Your link partner does not do autonegotiation, and this transceiver > > type > > does not report the sensed link speed. > > End of basic transceiver information. > > > > So why are the results of 'mii-tool' and 'mii-diag' different (I would > > expect the same)? > > > > Is it possible for these types of cards to autonegotiate to 100/full? > > How? > You might have a bad PHY. You might have a bad cable. If you flip the > cable around, does the output of mii-tool on the two ports flip around > too? If so, suspect the cable since that would happen if one of the > twisted pairs was bad. I did try flipping the cable around and the output was the same. I also tried a gig-crossover cable and that did not change the outcome either. I suspect it is a bad PHY. I attempted to pin the speed/duplex to 100/full (on both hosts) and neither node could ping the other node, though I could at 10/half. I have since abandoned these cards and purchased two gigabit ones - they autonegotiate to 1000/full without issues. Thanks for the info and assistance. Sincerely, -- Matt Zagrabelny - mzagrabe@xxxxxxxxx - (218) 726 8844 University of Minnesota Duluth Information Technology Systems & Services PGP key 1024D/84E22DA2 2005-11-07 Fingerprint: 78F9 18B3 EF58 56F5 FC85 C5CA 53E7 887F 84E2 2DA2 He is not a fool who gives up what he cannot keep to gain what he cannot lose. -Jim Elliot
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