12-07-2004 11:27 AM - edited 03-02-2019 08:27 PM
Hi,
I am having issues with Cisco 2924XL switch,
Its keep giving me these messages on console,
00:38:44: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/1
(not full duplex), with SIP00036B75B6DE Port 1 (full duplex).
00:39:44: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/1
(not full duplex), with SIP00036B75B6DE Port 1 (full duplex).
My current IOS version is "c2900xl-c3h2s-mz.120-5.WC10.bin"..
Please advice me how can I rectify this problem.
Regards,
Dennis
Solved! Go to Solution.
12-07-2004 01:05 PM
Set port f0/1 to full duplex on the 2924.
12-07-2004 01:00 PM
Did you check the duplex config. of the device connected on port f0/1?
12-07-2004 01:31 PM
The device connected to the port 0/1 is Netgear switch, and on my Cisco Switch I put auto, doesn't mean it should negotiate the duplex settings,,
12-07-2004 01:40 PM
Experience has shown that auto negotiation between different vendors is very hit and miss. Best bet is to hard code the speed and duplex on the Cisco equipment to avoid any conflicts like you are seeing.
12-08-2004 03:15 AM
The autonegotiation usually works well, but only if both sides support it and are configured for it. If one side is configured auto, and the other side is forced (or does not support auto), then autonegotiation does not take place. In this case, the auto side reverts to the default, which is half-duplex.
The result is that if one side is auto, and the other side is forced full-duplex, then there will be a duplex mismatch. I'm pretty sure that is what was happening here.
Kevin Dorrell
Luxembourg
12-07-2004 01:05 PM
Set port f0/1 to full duplex on the 2924.
12-07-2004 01:41 PM
Glen,
Thanks ....Issue resolved..Can u plz tell me why the port is not working on auto, it should auto negotiate the prot settings.
12-08-2004 05:27 AM
Better look at the netgear box... Could you verify the auto configuration there, or the fallback procedure for that switch?
12-08-2004 08:52 AM
From the message you are receiving it looks like you have another CDP-speaking device connected to the Netgear switch. Your speed/duplex settings may be OK, but what you are seeing is the CDP messages (which are layer-2 multicast) from the device SIP00036B75B6DE that I assume is an IP Phone with SIP software(?) that is running at Full Duplex whilst your FastEthernet0/1 port is running at half duplex.
Andy
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