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Catalyst 3750-E and Catalyst 3560-E Switch Hardware Installation Guide
OL-9774-03
Chapter 4 Troubleshooting
How to Clear the Switch IP Address and Configuration
• If a remote device does not autonegotiate, configure the duplex settings on the two ports to match.
The speed parameter can adjust itself even if the connected port does not autonegotiate.
Autonegotiation and NIC Cards
Problems sometimes occur between the switch and third-party network interface cards (NICs). By
default, the switch ports and interfaces are set to autonegotiate. It is common for devices like laptops or
other devices to be set to autonegotiate as well, yet sometimes autonegotation issues occur.
To troubleshoot autonegotiation problems try manually setting both sides of the connection. If this does
not solve the problem, there could be a problem with the firmware or software on your NIC card. You
can resolve this by upgrading the NIC card driver to the latest version available from the manufacture.
Cabling Distance
If the port statistics show excessive FCS, late-collision, or alignment errors, verify that the cable
distance from the switch to the connected device meets the recommended guidelines. See the
“Cable and
Adapter Specifications” section on page B-5 for cabling guidelines.
How to Clear the Switch IP Address and Configuration
If you have configured a new switch with a wrong IP address, or if all of the switch LEDs start blinking
when you are trying to enter Express Setup mode, you can clear the IP address that is configured on the
switch.
Note This procedure clears the IP address and all configuration information stored on the switch. Do not
follow this procedure unless you want to completely reconfigure the switch.
Follow these steps to return your switch to the factory default settings:
1. Press and hold the Mode button (Figure 1-1 on page 1-3).
The switch LEDs begin blinking after about 2 seconds. If the switch is not configured, the LEDs
above the mode button turn green. You can omit this step and run Express Setup to configure the
switch.
2. Continue holding down the Mode button. The LEDs stop blinking after an additional 8 seconds, and
then the switch reboots.
The switch now behaves like an unconfigured switch. You can configure the switch by using Express
Setup as described in the switch getting started guide that is included with the switch.
You can also configure the switch by using the CLI setup procedure described in the Configuring the
Switch with the CLI-Based Setup Program appendix.
