So you’ve bricked your Linksys SRW2024?
Apparently many users have issues upgrading the firmware on this switch. Most realize once after applying the latest update and rebooted, the switch no longer responds and the management interface cannot be accessed. This is because you will need to first apply the boot firmware before you can apply the OS.
At this point, you have no choice but to access and restore the switch via the console port.
Not your regular console cable
If you read the official documentation for the switch, the console cable specified is a “null modem” serial cable. This is WRONG! You will need a “straight through” or “modem” serial cable. The difference between the two is that the null modem cable has the pins 2-3 ie. RX & TX flipped, where as for the straight through cable all pins are 1 to 1.
Finding this cable can be difficult. So a clever way to construct one is to use two cisco console cables and an inline Rj45 coupler as shown below.
Once you have the cable follow the below steps to recover.
How to recover
- First download the old firmware “runtop-10086.ros“. You should be able to find this via some simple googling
- Go download Extra Putty. This version of putty gives you the needed xmodem transfer function in your next steps
- Connect your console cable to the switch using baud rate 38400, 8-N-1.
- Power on the switch and you should get the following output
BOOT Software Version 1.0.0.03 Built 08-Jun-2004 09:48:10 CPU - FireFox 88E6218 ARM946E-S processor 64 MByte SDRAM. I-Cache 8 KB. D-Cache 8 KB. Cache Enabled. Autoboot in 2 seconds - press RETURN or Esc. to abort and enter prom.
If you waited for the timer to expire you will get the following error message saying that it could not recognized your new firmware. At this point you can wait a couple or more seconds or power cycle the switch again to get back to the prompt.
Preparing to decompress... Decompressing SW from flash HOSTG_rscode_file_load: could not load file
- Press ESC to enter the boot menu
Startup Menu [1] Download Software [2] Erase Flash File [3] Password Recovery Procedure [4] Set Terminal Baud-Rate [5] Back - Press 1 to download software
- In the menu choose files transfer then select XMODEM and upload the “runtop-10086.ros” firmware you have downloaded in your first step.
- Wait for the lengthy transfer to complete. This could take around 30mins so be patient.
- Reboot and your switch will now be accessible!
