Allied Telesis AT-x230-10GP Installation Manual page 66

Chapter 3: Installation
56
The default speed setting for the ports is Auto-Negotiation. This

setting is appropriate for ports connected to network devices that
also support Auto-Negotiation.
The default speed setting of Auto-Negotiation is not appropriate for

ports connected to 10BASE-T and 100BASE-TX network devices
that do not support Auto-Negotiation and have fixed speeds. For
those switch ports, you should disable Auto-Negotiation and set
the port's speed manually to match the speeds of the network
devices.
The 10/1000BASE-T and 100BASE-TX ports must be set to Auto-

Negotiation, the default setting, to operate at 1000 Mbps.
The default duplex mode setting for the ports is Auto-Negotiation.

This setting is appropriate for ports connected to network devices
that also support Auto-Negotiation for duplex modes.
The default duplex mode setting for the ports is Auto-Negotiation.

This setting is appropriate for ports connected to network devices
that also support Auto-Negotiation for duplex modes.
The default duplex mode setting of Auto-Negotiation is not

appropriate for ports connected to network devices that do not
support Auto-Negotiation and have a fixed duplex mode. You
should disable Auto-Negotiation on those ports and set their
duplex modes manually to avoid the possibility of duplex mode
mismatches. A switch port using Auto-Negotiation defaults to half-
duplex if it detects that the end node is not using Auto-Negotiation,
which can result in a mismatch if the end node is operating at a
fixed duplex mode of full-duplex.
Do not attach cables to ports of static or LACP port trunks until

after you have configured the trunks on the switch. Otherwise, the
ports will form network loops that can adversely affect network
performance