Allied Telesis AT-S62 - Manual (Page 112)

Chapter 6: Port Parameters
112 Section I: Basic Operations
4 - Negotiation
You use this selection to activate or deactivate Auto-Negotiation on a
twisted pair port. This parameter has the two settings Auto and
Manual. If you select Auto, a twisted pair port uses Auto-Negotiation to
set its speed, duplex mode, and MDI/MDI-X settings. This is the
default setting. If you select Manual, additional options appear in the
menu for manually configuring these port settings. If you are
configuring a fiber optic port, the only setting available is Manual.
You should note the following concerning the operation of Auto-
Negotiation:
ˆ In order for a twisted pair port to successfully Auto-Negotiate its
duplex mode with an end node, the end node should also be using
Auto-Negotiation. Otherwise, a duplex mode mismatch can occur.
A switch port using Auto-Negotiation defaults to half-duplex if it
detects that the end node is not using Auto-Negotiation. This can
result in a mismatch if the end node is operating at a fixed duplex
mode of full-duplex.
To avoid this problem, when connecting an end node with a fixed
duplex mode of full-duplex to a switch port, you should disable
Auto-Negotiation on the port and set the port’s speed and duplex
mode manually.
ˆ When the port is set to Auto-Negotiate, the MDI/MDI-X setting is
locked at auto-MDI/MDI-X. The switch automatically determines
the correct MDI/MDI-X setting. You cannot manually set MDI/MDI-
X manually.
ˆ When Auto-Negotiation is disabled on a twisted pair port, the auto-
MDI/MDI-X feature on a port is also disabled, and the port defaults
to the MDI-X configuration. If you disable Auto-Negotiation and set
a port’s speed and duplex mode manually, you might also need to
set the port’s MDI/MDI-X setting as well.
5 - Speed
This selection is used to set the speed of a twisted pair port. It only
appears when option 4 - Negotiation is set to Manual. The possible
settings are:
0010 10 Mbps
0100 100 Mbps
You cannot change the speed of a fiber optic port.
Note
Ports 49R and 50R on an AT-8550GB Series switch must be set to
Auto-Negotiation to operate at 1000Mbps. You cannot manually
configure these ports to 1000Mbps.