Error added: 2005-09-14T21:35:07Z
The %CDP-4-DUPLEX_MISMATCH messages may be generated repeatedly when Cisco Discovery Protocol (CDP) has discovered a mismatch of duplex configuration between CDP neighbors. It can also occur when switches are separated by a non-Cisco switch or hub. If CDP version 2 reports the link as a half-duplex when a port or interface on a CDP-enabled device has been configured or auto negotiated to full-duplex, the alternate device may not support CDP version 2. This causes the error to occur. CDP is useful for detecting errors as well as port and system statistics on neighboring Cisco devices. CDP is Cisco proprietary and works be sending packets to a well-known MAC address 01-00-0C-CC-CC-CC. # To disable CDP version 2, issue the no cdp advertise-v2 command. # To check the CDP version running on the device, issue the show cdp command.
CDP has detected a duplex mismatch for a connection between two cisco devices. Set the duplex to be the same on both sides (i.e. full or half duplex, hard coded on both sides).
no cdp log mismatch duplex
It is not a well answer .... canot give duplex half or full in real environment.. because far a while it down the network so...dangerous for back bone network..
It has to be a duplex mismatch detected by CDP... check the MAC address in the log against the CDP Neighbour details, then set them to both be the same. There may be issues if you have a 10 meg device on the network, as this can not run at full duplex.
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