2 Replies Latest reply on Jul 7, 2013 6:11 AM by gplayers

    ESXi & Cisco CM7: CDP Duplex Mismatch on Switch

    DanFidelus Lurker


      Hello everyone - This is my first post so thank you for the help in advance. I have two Cisco CM7x servers running in ESXi with the ESXi server directly connected to a Cisco 3550 switch.



      The issue here is that the 3550 is detecting a duplex mismatch with the Cisco CM server. The switch is detecting CM as half duplex, but all configurations (in ESXi and CM) are set for 100/Full. Don't know if this is related, but I read somewhere that spanned CDP traffic from any Cisco device (router, CM, etc.) will show duplex mismatch on the spanned port that's listening on the traffic..?



      Has anyone encountered this issue? Again, Cisco CM eth0 is hardcoded for 100/Full, ESXi vmnic is hardcoded for 100/Full, and the switch port is also hardcoded for 100/Full. If this is related to the information I mentioned above, then I'll just go ahead and disable CDP on the connected interface. Thanks again in advance.



      - Daniel



        • 1. Re: ESXi & Cisco CM7: CDP Duplex Mismatch on Switch
          shockinac Lurker

          I experienced this duplex mismatch problem using ESXi and cucm 7.0.2.  The problem only happened with the Pub showing up as half duplex at the switch, no matter what I set it to.  The Pub cli "show network eth0" showed 100/full no matter what.

          Finally, I shut the CUCM down. Went to the VMware settings for the Pub and deleted the existing NIC.  I reinstalled an E1000 NIC.  When I restarted the Pub, it was connected at 1000/full, which is what I wanted.  It's possible reinstalling the flex NIC type  may also work.


          Message was edited by: shockinac

          • 2. Re: ESXi & Cisco CM7: CDP Duplex Mismatch on Switch
            gplayers Lurker

            CDP needs to be disabled on the interface generating the error. What happens is ESXi is running the native switch of OS causing these errors. IE: (%CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/0 (not full duplex)


            To fix this little issue run the following on the interface in question.
            "NO CDP ENABLE" for newer IOS versions "NO CDP ADVERRTISE-V2