A step by step guide on how to update Cisco router DSL firmware.
Cisco ISR router DSL firmware can be a source of frustration for ADSL users and is notorious for it’s its poor ADSL 2+ support in older models. Fortunately a firmware upgrade usually sorts this out and addresses the lack of ADSL 2+ support. However unlike your average DSL router Cisco routers are a bit more complicated than just clicking the update firmware button in a GUI. Here’s how to update Cisco router DSL firmware (pretty much the same as updating iOS if you have done that).
1. To update Cisco router DSL firmware first check the firmware version you are currently running using ‘show dsl int’ as per the following screen shot:
2. Download the latest firmware version from the Cisco website assuming there is a newer version available http://software.cisco.com/download/navigator.html (you will need a login for this).
3. Download and install a TFTP server. I usually use tftpd32 (it has 32-bit and 64-bit versions).
4. Copy your downloaded firmware to the tftp server’s source directory and in some cases if it isn’t already a .bin file rename it with .bin extension (don’t rename any other part, the name is important).
5. Login to the router with an ssh or telnet client (I use putty for this). Run the following command:
copy tftp flash
It will then prompt for a server, enter the IP of your tftp server. Next it will prompt for the name of the firmware, just type in the name of the new firmware file. If prompted to rename it don’t and if prompted to delete existing firmware also don’t.
6. Reboot the router, either manually or using the ‘reload’ command.
7. When the router comes back up you can run ‘show dsl int’ again and you should see the router is running with the new firmware. If it isn’t using the new firmware either it is not a valid file or the existing version was newer.