Upgrading the adsl modem firmware on Cisco 877W router

In order to ensure compatibility and stability with your ISPs equipment in the exchange, it is at times necessary to upgrade the adsl modem firmware on your Cisco router. Download the appropriate firmware for your router (in this case a Cisco 877W). It is essential you get the correct version so take care to make sure you have the correct one. Some older updates can be found here:

ftp://ftp.cisco.com/pub/access/800/

You will need a Cisco Smartnet subscription to get the latest firmware.

Once you have downloaded the firmware (in this case adsl_alc_20190_4.0.018.bin), you need to rename the file to adsl_alc_20190.bin

Telnet into your router and check the current firmware version by running the command:

show dsl interface

From the output of the command you can see under the ‘Operation FW’ section it shows the current firmware file and version, and also that under the ‘FW Source’ it shows the location as embedded.

Next we need to copy the new firmware file to the flash memory on the router using tftp. You can use the Cisco tftp server software to do this. or alternatively download Solarwinds free tftp server software.

Place the firmware file you renamed earlier into the tftp servers root directory and then issue the following command on your router:

copy tftp flash 

fill in the ip address for your tftp server and the source and destination filename adsl_alc_20190.bin

issue the reload command to restart your router:

reload

Once your router is back up telnet into it again and run the following command again to see the result:

show dsl interface

As you can see the ‘Operation FW’ now shows the new firmware version, and the ‘FW Source’ as external. If for any reason you have a problem with the updated firmware, you can easily roll back to the embedded version by deleting the adsl_alc_20190.bin from the routers flash memory.

This can be done by issuing the following command:

delete adsl_alc_20190.bin

When asked to confirm the file deletion just press ‘Enter’