[vortex] correct setting for 100Mbps full-duplex on 3Com 905C

Donald Becker becker@scyld.com
Wed Jan 15 08:42:01 2003


On Wed, 15 Jan 2003, [iso-8859-15] Jürgen Sandner wrote:

> We use 3COM 905B and 905C Network Adaptors at work, connected to CISCO 
> Catalyst 3500 Switches.
> Autosensing doesn't work (data loss, errors), but not only under Linux, but 
> also under Windows NT.

Autonegotiation, or speed autosensing?  My guess is that the switch is
set to forced-full-duplex, which is a flawed concept.

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

> We have to configure the Cards to 100 Mbps full-duplex or 10 Mbps
> full-duplex, and the switch port of course the same.

If your switch has broken autonegotiation, set it to 100Mbps, half duplex.
Non-autonegotiation Ethernet *is* half duplex.  Setting forced-full
duplex is non-standard.

> What is the correct way to this under Linux?
> I checked http://www.scyld.com/network/vortex.html, but the setting of the 
> option-field for 100 Mbps is not really clear to me.

It depends on your driver version.  If you are using the Scyld driver
release you can use
   mii-diag eth0 -F 100baseTx-FDX

If you are using another release, you should use the instruction with
that driver.

-- 
Donald Becker				becker@scyld.com
Scyld Computing Corporation		http://www.scyld.com
410 Severn Ave. Suite 210		Scyld Beowulf cluster system
Annapolis MD 21403			410-990-9993