This article describes the procedures for upgrading the Cisco IOS software image on the access router platform. 2600 and 3600 series router upgrade examples also apply to the router platforms listed below. cisco IOS software file names may change depending on the Cisco IOS software version, feature set, and platform. This article illustrates the following Cisco series routers.
Cisco 1000 Series Routers
Cisco 1400 Series Routers
Cisco 1600 – R-Series Routers
Cisco 1700 Series Routers
Cisco 2600 Series Routers
Cisco 3600 Series Routers
Cisco 3700 Series Routers
Cisco 4000 Series Routers
Cisco 4700 Series Routers
Cisco AS5300 Series Routers
Cisco MC3810 Series Routers
The information in this document is based on Cisco IOS software version 12.0 or later.
Before you start
Step 1: Install TFTP server
A Small File Transfer Protocol (TFTP) server or Remote Copy Protocol (RCP) server application must be installed on the TCP/IP-ready workstation or PC. Once the application is installed, a minimum configuration must be performed.
First, the TFTP application must be configured to run as a TFTP server, not as a TFTP client.
The outbound file directory must be specified. The Cisco IOS software image is stored in this directory (see Step 2 below). Most TFTP applications provide installation routines to assist with these configuration tasks.
Note: The TFTP server is included on the Software Features Suite CD and can be used on PCs running Windows 95, Windows 98, NT4.0, and Windows 2000. For other operating systems, many TFTP or RCP applications are available from independent software vendors, or shareware TFTP or RCP applications are available from public resources on the World Wide Web. The TFTP server applications on the Software Feature Suite CD are also available on CCO.
Download TFTP server for Windows 95, Windows 98, NT4.0, and Windows 2000.
Step 2: Select the Cisco IOS software image
Verify that the Cisco IOS system software image you downloaded supports both your hardware and the required software features. You can find this information through Cisco Software Advisor. Before downloading the software version of your choice, make sure that your router has enough dynamic RAM (DRAM) and flash memory to store the Cisco IOS software image. You can find the recommended minimum DRAM and flash memory in the release notes for each Cisco IOS software release and in the Cisco Software Center IOS Upgrade Planner.
For more information on how to select the correct software version and feature settings, see ” How to Select a Cisco IOS Software Version”.
Step 3: Download Cisco IOS software image
Download the Cisco IOS software image from Cisco IOS Upgrade Planner to your workstation or PC.
Upgrade steps for Cisco 2600 series routers
Establishing a console session to the router
Verify that the TFTP server has an IP connection to the router
Copy the new image to the 2600 series router’s flash memory via TFTP server
Step 1: Establish a console session to the router
Even though it is possible to connect to the router via telnet, we strongly recommend using the console port to connect directly to the router. The reason is that if some failure occurs during the upgrade, it may be necessary to be physically close to the router in order to reboot it. Also, during the router upgrade step, the telnet connection will be lost when the router is rebooted.
A reversed cable (usually a flat black cable) is used for the connection and the console port of the router is connected to one of the COM ports of the PC.
Once the PC is connected to the router’s console port, you need to enable HyperTerminal on the PC and use the following settings.
Speed 9600 bits per second
0 parity bits
1 stop bit
No Flow Control
Note: If you are getting invalid characters in your HyperTerminal session, this means that you have not set the HyperTerminal properties correctly, or that the router’s config-register is set to a non-standard value that allows the console to connect at speeds higher than 9600 bps. The router must be reloaded for the configuration register to take effect. Once you are sure that the console speed is set to 9600 bps on the router side, you should check the HyperTerminal property above. For more information on setting the hyperterminal properties, see “Applying the correct terminal emulator settings for console connectivity”.
Once you have connected the console port of the router, you may notice that the router is in ROMmon mode or Boot mode. These two modes are used for the recovery and diagnostic steps. If you do not see the usual router prompts, you should follow the advice below to proceed with the upgrade step configuration.
1. The router boots in rommon mode, and the following message appears when you issue the 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 that the flash memory is completely empty or the file system is corrupted. Please refer to the “Xmodem console download procedure using ROMmon”.
Note: You may also want to review the Guided Failure Recovery procedure.
2. The router boots up in boot mode and the following message appears 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 see the above error message in the console output, it means that the flash memory is completely empty or the file system is corrupted. Please copy a valid image to the flash memory by performing the steps provided in this article.
Note: You may need to review the “Guided Failure Recovery Procedure”.