3com 3CRWE776075 Manuel D’Utilisation

 

34 Troubleshooting

There may be a full-duplex / half-duplex mismatch between the switch 
and a connected device.

Ensure that the connected device has either:

■

Auto-negotiation enabled, or

■

The ports are configured for half-duplex operation

Make sure that:

■

The PC’s IP address is in the same IP subnet as the switch.

■

The PC’s subnet mask matches the subnet mask of the switch.

Make sure that:

■

The switch’s IP address is in the same IP subnet as the DHCP server.

■

The switch’s subnet mask matches the subnet mask of the DHCP 
server.

An LTK error is caused by either of the following situations:

■

You are trying to activate an AP is already activated on another unified 
switch.

■

You are trying to activate an AP that was previously activated on 
another unified switch.

When an AP is activated on a unified switch, the AP is imprinted with a 
special security key (LTK) that is shared between the unified switch and 
the AP. An AP that has been activated by a unified switch will only 
communicate with that one switch. If you later wish to activate the AP on 
a different unified switch, you must clear the LTK by performing a Short 
Reset on the AP as described in “Resetting Access Points” on page 26.

If the problem persists refer to the more detailed troubleshooting 
information in your User’s Guide or on the 3Com Web site.