3Com 3CRWX120695A, Configuration Manual

Page: 79 / 728

Configuring and Managing Ports 79
Configuring Port
Operating
Parameters
Autonegotiation is enabled by default on a WX switch’s 10/100 Ethernet
ports and gigabit Ethernet ports.
You can configure the following port operating parameters:
„
Speed
„
Autonegotiation
„
Port state
„
PoE state
All ports on the WX4400 switches support full-duplex operating mode
only. They do not support half-duplex operation. Ports on the WX1200
switch support half-duplex and full-duplex operation.
3Com recommends that you do not configure the mode of a WX port so
that one side of the link is set to autonegotiation while the other side is
set to full-duplex. Although MSS allows this configuration, it can result in
slow throughput on the link. The slow throughput occurs because the
side that is configured for autonegotiation falls back to half-duplex. A
stream of large packets sent to a WX port in such a configuration can
cause forwarding on the link to stop.
You also can toggle a port’s administrative state and PoE setting off and
back on to reset the port.
10/100 Ports—Autonegotiation and Port Speed
WX 10/100 Ethernet ports use autonegotiation by default to determine
the appropriate port speed.
To explicitly set the port speed of a 10/100 port, use the following
command:
set port speed port-list { 10 | 100 | auto }
If you explicitly set the port speed (by selecting an option other than
auto ) of a 10/100 Ethernet port, the operating mode is set to full-duplex.
MSS allows the port speed of a gigabit port to be set to auto. However,
this setting is invalid. If you set the port speed of a gigabit port to auto,
the link will stop working.