Connecting To Devices That Do Not Autonegotiate; Setting Speed And Duplex Parameters - Cisco Catalyst 2950 Software Manual

Changing the Port Speed and Duplex Mode

Connecting to Devices That Do Not Autonegotiate

To connect to a remote 100BASE-T device that does not autonegotiate, set the duplex setting to Full or
Half, and set the speed setting to Auto. Autonegotiation for the speed setting selects the correct speed
even if the attached device does not autonegotiate, but the duplex setting must be explicitly set.
To connect to a remote Gigabit Ethernet device that does not autonegotiate, disable autonegotiation on
the local device, and set the duplex and flow control parameters to be compatible with the other device.

Setting Speed and Duplex Parameters

Beginning in privileged EXEC mode, follow these steps to set the speed and duplex parameters on a port:
Command
Step 1 configure terminal
Step 2 interface interface
Step 3 speed {10 | 100 | 1000 | auto}
Step 4 duplex {full | half | auto}
Step 5 end
Step 6 show running-config
Step 7
copy running-config
startup-config
Catalyst 2950 Desktop Switch Software Configuration Guide
10-2
Purpose
Enter global configuration mode.
Enter interface configuration mode, and enter the port to be
configured.
Enter the speed parameter for the port.
• The 10/100/1000 ports operate in 10 or 100 Mbps when they
are set to half- or full-duplex mode, but only operate in
full-duplex mode when set to 1000 Mbps.
The GBIC module ports operate only at 1000 Mbps.
•
100BASE-FX ports operate only at 100 Mbps in full-duplex.
•
The Catalyst 2950C-24 does not support the speed and
Note
duplex interface configuration commands in
IOS Release 12.1(6)EA2.
Enter the duplex parameter for the port.
The 10/100/1000 ports operate in either half- or full-duplex
•
mode when they are set to 10 or 100 Mbps, but when set to 1000
Mbps, they only operate in full-duplex mode.
100BASE-FX ports operate only at 100 Mbps in full-duplex.
•
The Catalyst 2950C-24 does not support the speed and
Note
duplex interface configuration commands in
IOS Release 12.1(6)EA2.
Return to privileged EXEC mode.
Verify your entries.
(Optional) Save your entry in the configuration file. This retains the
configuration when the switch restarts.
Chapter 10 Configuring the Switch Ports
78-11380-03