Cisco 2600 series IOS upgrade procedure

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Joined: 16/08/2008
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Cisco 2600 Series Routers Upgrade Procedure

  • Establish a console session to the router
  • Verify that the TFTP server has IP connectivity to the router
  • Copy the new image into the Flash memory of the 2600 Series Router through the TFTP server

Step 1: Establish a console session to the router

Even if it is possible to connect to the router through a telnet session, it is strongly recommended to be directly connected to the router using the console port. The reason is that if something goes wrong during the upgrade, it might be necessary to be physically located next to the router to power-cycle it. Moreover, the telnet connection will be lost while the router is rebooting during the upgrade procedure.

A rolled cable (usually a flat black cable) is used to connect the console port of the router to one of the COM ports of the PC.

Once the PC is connected to the console port of the router, you need to open Hyperterminal on the PC, and use the following settings:

Speed 9600 bits per second

8 databits

0 parity bits

1 stop bit

No Flow Control

Note: If you are getting any garbage characters in the hyperterminal session, this means that you have not set the hyperterminal properties properly, or the config-register of the router is set to a non-standard value for which the console connection speed is higher than 9600 bps.  Check the value of the config-register using the show version command (shown in the last line of the output) and ensure it is set to 0x2102 or 0x102. It is necessary to reload the router for a configuration register change to take effect. Once you are sure the console speed is set to 9600 bps on the router side, you should check the hyperterminal properties as above .

Booting Problems

Once you are connected to the console port of the router, you might notice that the router is either in ROMmon or Boot mode. These two modes are used for recovery and/or diagnostic procedures. If you do not see the usual router prompt, you should follow the recommendations below to proceed with the upgrade procedure installation.

  1. Router boots in rommon mode, and the following message appears when you issue dir flash: command.
    rommon 1 > dir flash: 
    device does not contain a valid magic number 
    dir: cannot open device "flash:" 
    rommon 2 >

    When you see the above error message, it means the Flash is empty or the filesystem is corrupted. A Xmodem console download procedure using ROMmon may then be necessary.

  2. Router boots in boot mode, with the following messages on the console:
    device does not contain a valid magic number
    boot: cannot open "flash:"
    boot: cannot determine first file name on device "flash:"

When you get the above error messages on the console output, it means the Flash is empty or the file system is corrupted. Copy a valid image on the Flash by following the procedures provided in this document.

Step 2: Verify that the TFTP server has IP connectivity to the router

The TFTP server must have a network connection to the router, and must be able to ping the IP address of the router targeted for a TFTP software upgrade. To achieve this, the router interface and the TFTP server must have:

  • an IP address in the same range, or


  • a default gateway configured.

To verify this, check the IP address of the TFTP server.

Step 3: Copy the new image into the Flash memory of the 2600 Series Router through the TFTP server

  1. Now that you have IP connectivity and can ping between the computer acting as a TFTP server and the router, you can copy the Cisco IOS Software image into the Flash.

    Note: Before copying, make sure you have started the TFTP server software on your PC and that you have the filename mentioned in the TFTP server root directory. We recommend that you keep a backup of the router/access server configuration before upgrading. The upgrade itself does not affect the configuration (which is stored in nonvolatile RAM (NVRAM). However, this might happen if the right steps are not followed properly.

    For RCP applications, substitute RCP for every occurrence of TFTP. For example, use the copy rcp flash command instead of the copy tftp flash command.

    2600> enable
    2600# copy tftp flash

    If necessary, you can copy an image from one device to another.

  2. Specify the IP address of the TFTP server.

    When prompted, enter the IP address of the TFTP server as in the following example:

    Address or name of remote host []?

  3. Specify the filename of the new Cisco IOS Software image.

    When prompted, enter the filename of the Cisco IOS Software image to be installed, as in the following example:

    Source filename []? c2600-i-mz.121-14.bin

    Note: The filename is case sensitive, so be sure to enter it correctly.

  4. Specify the destination filename.

    This is the name the new software image will have when it is loaded onto the router. The image can be named anything, but common practice is to enter the same image filename.

    Destination filename []? c2600-i-mz.121-14.bin

    Note: If you see the below error message:

    %Error copying tftp://
    (Not enough space on device)

    This indicates that there is not enough room available in Flash to copy the image. You need to erase a file(s) before copying the new image from the TFTP server.

  5. Upgrade the new image from a TFTP server

    2610#copy tftp flash
    Address or name of remote host []?
    Source filename []? c2600-i-mz.121-14.bin
    Destination filename [c2600-i-mz.121-14.bin]?y 
    Accessing tftp://
    Erase flash: before copying? [confirm]y !---If there is not enough
    !--- memory available, erase the Flash
    Erasing the flash filesystem will remove all files! Continue? [confirm]y
    Erasing device... eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
    eeeeeeeeee ...erased
    Erase of flash: complete
    Loading c2600-i-mz.121-14.bin from (via Ethernet0/0): !!!!!!!!
    [OK - 4501480/9001984 bytes]

    Verifying checksum...  OK (0xAC8A)
    4501480 bytes copied in 56.88 secs (80383 bytes/sec)

    The copying process takes several minutes; the time differs from network to network. During the copy process, messages are displayed to indicate which file has been accessed.

    The exclamation point "!" indicates that the copy process is taking place. Each exclamation point indicates that ten packets have been transferred successfully. A checksum verification of the image occurs after the image is written to Flash memory.

After you have upgraded the Flash, you need to reload the router using the reload command.

Before you reload the router, you need to check two things:

  • The value of the config-register - You can check this using the show version command. The value is shown in the last line of the show version output. It should be set to 0x2102.

      2610#configure terminal
      Enter configuration commands, one per line.  End with CNTL/Z. 
      2610(config)#config-register 0x2102 

  • The other files on the Flash - If the first file in the Flash is not the Cisco IOS Software image, but a configuration file or something else, then you need to configure a boot system statement in order to boot the specified image. Otherwise, the router will try to boot with the configuration file or the first file in the Flash; this will not work. If there is only one file in the Flash which is the Cisco IOS Software image, then this step is not necessary.

      2610#configure terminal
      Enter configuration commands, one per line.  End with CNTL/Z. 
      2610(config)#no boot system
      2610(config)#boot system flash c2600-i-mz.121-14.bin

Note: If you type the reload command, the router asks you if you want to save the configuration. You should be very cautious here. The reason is that if the router is in boot mode for instance, it is a subset of the full Cisco IOS software which is running and there is no routing functionality. Therefore, all the routing configuration is gone in the running configuration and if you save the configuration at this time, then you erase the good startup-configuration in NVRAM and replace it by the incomplete running-configuration. Save the configuration only if you are sure that you have the full configuration in the output of show run. It is NOT necessary to save the configuration to take into account the new config-register if this one has been changed previously. That is done automatically.

System configuration has been modified. Save? [yes/no]: y 
Building configuration...
Proceed with reload? [confirm]y

Verify that the router is running with the proper image. After the reload is complete, the router should be running the desired Cisco IOS Software image. Use the show version command to verify.

2610#show version
00:22:25: %SYS-5-CONFIG_I: Configured from console by console
Cisco Internetwork Operating System Software 
IOS (tm) C2600 Software (C2600-I-M), Version 12.1(14), RELEASE SOFTWARE (fc1)
Copyright (c) 1986-2002 by cisco Systems, Inc.
Compiled Mon 25-Mar-02 20:33 by kellythw
Image text-base: 0x80008088, data-base: 0x80828788

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

2610 uptime is 22 minutes
System returned to ROM by reload
System image file is "flash:c2600-i-mz.121-14.bin"

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