Sun's hme and later fast ethernet adaptors support full-duplex ethernet.
There are several ways of changing the default settings and force
full-duplex mode; you may need to alter your switch settings as well.
The problem with changing this setting is that it disables auto
negotiation. Usually, this causes switches to fall back to half-duplex
mode unless they are also configured to use full duplex mode.
It is usual best to leave the settings alone and have both switch and
Sun auto-negotiate unless problems arise.
Setting through /etc/system
Setting with ndd
ndd -set /dev/hme adv_100hdx_cap 0
ndd -set /dev/hme adv_100fdx_cap 1
ndd -set /dev/hme adv_autoneg_cap 0
In case you have multiple instances, you need to select the specific
hme instance first, e.g., use the following to select hme1:
ndd -set /dev/hme instance 1
If you need to query the device, you can interrogate various variables
such as ``link_status'', ``link_speed'', etc.
Setting "adv_autoneg_cap", not necessarily changing it, will cause
re-negotiating of link speed/duplex settings.
The dfme device cannot configured using /etc/system but are configured
either with ndd (but on per-device nodes /dev/dfme0, dev/dfme1) or
by editing dfme.conf.