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Cisco 3600 series router does not boot to the image specified in the boot system command due to incorrect command syntax

Core Issue

The command syntax is incorrect, even though the same syntax works on other Cisco routers, because the syntax requirement for the Cisco 3600 series router is different from other models.


To resolve this issue, perform these steps:

  1. If a Cisco 3600 series router has more than one image in Flash, and the image the user wants to boot from is not the first image in Flash or if the image is on a PCMCIA Flash card, a boot system command is required.

    To ensure that the boot system command works properly, always use this syntax:

    boot system flash <device:><filename>

    For example, to boot an image named c3640-i-mz.122-10.bin from the internal Flash, the command would be as shown:

    router(config)#boot system flash flash:c3640-i-mz.122-10.bin
  2. To boot to a file of the same name from a Flash card in slot0, the command would be as shown:
    router(config)#boot system flash slot0:c3640-i-mz.122-10.bin
  3. If the internal Flash is partitioned and the file is on the second partition, the command would be as shown:
    router(config)#boot system flash flash:2:c3640-i-mz.122-10.bin

    Note: The filename must be exactly the same as it is displayed in the output of the show flash command. It is case sensitive.

    The use of other syntaxes (such as these three examples) may cause the router to not boot to the desired image, even though the commands are accepted when configuring the router:

    boot system flash:c3640-i-mz.122-10.bin
    boot system flash c3640-i-mz.122-10.bin
    boot system slot0:c3640-i-mz.122-10.bin
  4. If the boot system command (which is not working properly) exists in the configuration, remove it by issuing the no<current boot sytem command> global configuration command.

    For example, to remove the boot system slot0:c3640-i-mz.122-10.bincommand, issue the no boot system slot0:c3640-i-mz.122-10.bin global configuration command. Then configure the correct syntax.

  5. Verify that the correct command is in place by issuing the show running-config command.
  6. Make sure to save the configuration after the correct boot systemcommand is in place by issuing the write memory command.
  7. Verify that the correct command is saved to the startup configuration by issuing the show startup-config command.

    Note: If only one image is present in the internal Flash, or if the desired image is the first file in the internal Flash, the boot system command is not required. This is because the router boots to the first image in internal Flash by default.

Community Member

Thanks for clarifying the syntax.  Here's another helpful resource on the Cisco 3600, including password recovery documentation