Re: Intel 82557 half-duplex issues, SIOCSIFMEDIA: Device not configured

[Dimitry Andric <dim@xs4all.nl>]

On 2001-12-07 at 16:36:25 Smith, Steve wrote:

SS> I can't get my Intel 82557 adapters to force half-duplex.  I have a
SS> DLINK 100/10 hub and a 3Com 100/10 hub which I tried and been
SS> unsuccessful with both.  I can get the adapter to work in autoselect but
SS> I get the following when trying to set half-duplex:

SS> vbxopenbsd01# ifconfig fxp1 media 100baseTX mediaopt half-duplex
SS> ifconfig: SIOCSIFMEDIA: Device not configured

I think this is the same issue as I've seen lately with FreeBSD: there
is no specific mediaopt for half-duplex, because it's the default.
Only if you want full-duplex, you need to specify it explicitly.

So:

  ifconfig fxp1 media 100baseTX mediaopt full-duplex

sets 100 Mbit/full duplex, and

  ifconfig fxp1 media 100baseTX

sets 100 Mbit/half duplex. It seems that the fxp(4) man page is
therefore incorrect, or at least unclear, as it mentions:

  media 100baseTX mediaopt half-duplex
    Set 100Mbps (Fast Ethernet) operation and force half-duplex mode.

as a possible option to ifconfig(8).

A much clearer explanation of this is given in the dc(4) man page
(using this card in my laptop at the moment):

  100baseTX     Set 100Mbps (Fast Ethernet) operation.  The mediaopt
                option can also be used to enable full-duplex
                operation.  Not specifying full duplex implies
                half-duplex mode.

Also, the ifmedia(4) man page says:

  The following media options are shared by all link types:

    IFM_FDX   Place the device into full-duplex mode.  This option
              only has meaning if the device is normally not
              full-duplex.  [full-duplex, fdx]

    IFM_HDX   Place the device into half-duplex mode.  This option
              only has meaning if the device is normally not
              half-duplex.  [half-duplex, hdx]

Cheers,
--
Dimitry Andric <dim@xs4all.nl>
PGP Key: http://www.xs4all.nl/~dim/dim.asc
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