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Unable to execute commands on Cisco 2504

Discussion in 'General Cisco Certifications' started by two5om, Jun 14, 2007.

  1. two5om

    two5om New Member

    Heya all,

    I have x3 Cisco 2504 routers and haven't powered them up for a while.

    I powered up the 3 routers only to find that 2 of the 3 successfully load up IOS where one of them takes a really long time to boot up.

    When it does I'm only prompt with an un-usual CLI prompt which is ">".

    At this prompt no IOS commands are being recognised.

    Any suggestions?

  2. NetEyeBall

    NetEyeBall Kilobyte Poster

    The > prompt indicates you are in User mode. You need to type enable to go into Privileged Mode.

    What happens when you type in ? from the > prompt?
    Certifications: CCNA, A+, N+, MCSE 4.0, CCA
    WIP: CCDA, CCNP, Cisco Firewall
  3. Spice_Weasel

    Spice_Weasel Kilobyte Poster

    You might be in rommon mode. If the IOS image is missing or corrupted the router will boot into rommon mode, which looks like this:

    rommon 1 >

    or this:


    You can tell rommon by typing ? and hit enter, there will only be a limited number of low level commands such as confreg and reload.

    If you don't see confreg or reload, but see commands such as login, ping or show you are in user mode, as NetEyeBall noted.

    Certifications: CCNA, CCNP, CCIP, JNCIA-ER, JNCIS-ER,MCP
  4. two5om

    two5om New Member

    Hi Guys,

    Firstly, thanks for the replies.

    I can confirm that I am not in user mode as only ">" is displayed as a prompt where I used to be first presented with user mode "router>".

    I'm unable to execute any low level user mode commands.

    When I try and execute the "show version" command I am prompt with the following error:

    0: jmp @#0x10003A6
    Trace trap at 0x10003A6 (PC)

    I tried what Spice_Weasel suggested and entered "?" and I was presented with the following options:

    $ Toggle cache state
    B [filename] [TFTP Server IP address | TFTP Server Name]
    Load and execute system image from ROM or from TFTP server
    C [address] Continue execution [optional address]
    D /S M L V Deposit value V of size S into location L with modifier M
    E /S M L Examine location L with size S with modifier M
    G [address] Begin execution
    H Help for commands
    I Initialize
    K Stack trace
    L [filename] [TFTP Server IP address | TFTP Server Name]
    Load system image from ROM or from TFTP server, but do not
    begin execution
    O Show configuration register option settings
    P Set the break point
    S Single step next instruction
    T function Test device (? for help)

    Deposit and Examine sizes may be B (byte), L (long) or S (short).
    Modifiers may be R (register) or S (byte swap).
    Register names are: D0-D7, A0-A6, SS, US, SR, and PC

    Any suggestions?

  5. BosonMichael
    Highly Decorated Member Award

    BosonMichael Yottabyte Poster

    Yep, you're in ROM monitor mode. No idea what's causing your trace trap... bad memory? just a guess.
    Certifications: CISSP, MCSE+I, MCSE: Security, MCSE: Messaging, MCDST, MCDBA, MCTS, OCP, CCNP, CCDP, CCNA Security, CCNA Voice, CNE, SCSA, Security+, Linux+, Server+, Network+, A+
    WIP: Just about everything!
  6. Headache

    Headache Gigabyte Poster

    I hate it when this happens, because it's a real b1tch to get it sorted.

    I'm guessing that the router is unable to boot from flash (for whatever reason). Maybe the resident image has become corrupted or maybe the flash memory stick has gone bad. It could be any number of things. There's an outside possibility that the config register is wrong and needs changing back to the default bootup version.

    You've got a few options there you can try.

    Option B should allow you to load or execute system image from ROM or tftp server.

    Option O may also allow you to change the config register settings back to 0x2102. But if the resident image is bad, that wouldn't help you very much.

    If it turns out that it is as a problem with the image, then you can download a new image from cisco (or somewhere else) and then using option B, see if you load the new image on to the flash directory. I believe the correct procedure is as follows:

    Download a tftp server from the net (I use solarwinds)
    Download a new image from cisco on to the tftp server
    Copy tftp flash
    Boot system flash (this will ensure that the router boots the correct image on the next reload. If you forget to do this then you'll end up in the same position you're in now).
    Copy run start (to retain the boot variable config changes)
    Reload (to reset the router)
    Sh ver (to verify new image and ios version).

    Certifications: CCNA
  7. two5om

    two5om New Member

    Hey all,

    I have managed to resolve the problem as it was due to a configuration register issue.

    At ROMMON mode I performed the following to resolve the issue:

    >o/r 0x2102

    Thanks again


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