connect a terminal to the console port, and look for any of the following system messages:

    c4k_chassis-3-linecardmuxbuffertosupalignmentwron g

    c4k_chassis-3-linecardnotvalidinslot

    c4k_chassis-3-modulenotsupporthalf

    c4k_iosintf-5-stalephyport

    c4k_iosmodportman-4-inlinepowerovermax

    if you observe any of these messages, follow the suggestion for that message.

    some problems can be solved by resetting the switching module. use the hw-module module [n] reset command to reset a switching module, or remove and re-insert the switching module, which resets, restarts, and power cycles the switching module. the show module and show diagnostics online module commands can also provide information useful in solving problems with ports on individual modules.

    not all software versions support all switching modules. if you are having trouble with a module, refer to the software release notes to be sure that it is supported by your software.