[vortex] 3c905c 10Mb duplex queries

[Donald Becker]

On Sun, 23 Feb 2003, Richard Scobie wrote:

> I have just comissioned a 10Mb internet connection via a Linux firewall 
> box using a 3c905c to a copper-fibre convertor, (still trying to find 
> out the make and model - it's locked in a steel cabinet)
> 
> The suppliers of the connection claim the connection is full duplex and 
> a check of the boot log shows that the copper fibre convertor returns a 
> link partner code of 0021 and the 3c905c is initialised as half duplex.
> 
> As far as I can tell, 0021 is not a valid code - 0020 is 10baseT.

...1 is the 'technology type' indicator for Ethernet.
(There are no other 'technology types', so my guess is that these five
bits will be wasted for all time.  They should have forseen faster link
speeds rather than other network types.)

> Using mii-diag, I can force full duplex and an FTP download from a site 
> a couple of hundred miles away shows "39717604 bytes received in 35.2 
> secs (1.1e+03 Kbytes/sec)". This seems to be a fair speed, but when I 
> look at ifconfig stats

Use the stats from /proc/net/dev -- the 'ifconfig' program is reading
from there anyway.

> RX packets:117503 errors:0 dropped:0 overruns:1 frame:0
> TX packets:14117 errors:0 dropped:0 overruns:0 carrier:14109

What driver version are you using?
You can verify that the driver you are using actually sets the full
duplex bit by running 'vortex-diag -a'.

> I am a little confused, as I would not expect to see the throughput that 
> I do, if the setup is mis-configured in full duplex.

Media converters are notorious for violating specs in one way or
another.  This may still be the driver correctly reporting a problem
with the link beat.  But the first thing to check out is that the driver
you are using correctly configures the transceiver.

-- 
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