Fix Linksys LGS552 / LGS552P Login Stuck at 90%

I deployed several LGS552 / LGS552P switches at our office since they are quite powerful and great value for money. Everything was running great... until today. For some reason, these switches have firmware that triggers an account lockout after 180 days. This isn't configurable via the web UI, so you have no idea anything is wrong until suddenly you're trying to log in and the progress bar is stuck at 90%.

If you haven't disabled telnet, you're in luck! You can disable the account lockout using telnet (see part 2 below). If, like me, you've disabled telnet on the switch (because you like to reduce the possible attack surface of devices on your network), you face a much worse scenario: according to Linksys community support, the only way forward is a factory reset. Being 9000 km away from my switches, this wasn't an option for me. Luckily I discovered another solution that doesn't involve rebooting OR factory resetting, so there is zero downtime for your users and no configuration loss.

Part 1: Restoring web access

You'll need Chrome for this as we'll be using DevTools.

  1. Login to your switch as normal. When you get stuck at the 90% login screen, press F12 to open DevTools.
  2. Click the "Sources" tab and expand the folders to locate js/home.js. Click it.
  3. Press Ctrl+F and type "top.isPasswordExpired". You should end up around line 1531 or thereabouts.
  4. Click the line number to set a breakpoint (it should turn blue).
  5. Refresh the login page. This time you should get a "Paused in debugger" message.
  6. Click the "Console" tab in DevTools and type 
    _top.isPasswordExpired = false
  7. Go back to the "Sources" tab and click the line number again to remove the breakpoint.
  8. Click the "Continue" icon on the "Paused in debugger" message.
  9. You should now be logged in. Go to the settings and enable telnet to continue.

Part 2: Disable password aging

Now that telnet is enabled, you can use it to turn off password aging to prevent this from happening in the future.

  1. Telnet to the switch.
  2. Login with your regular username / password. Ignore the prompt to change it.
  3. At the "Linksys Switch Menu", press Ctrl+A to enter the command line.
  4. Type the following (you'll be prompted to login again):
    lcli
conf t
passwords aging 0
  5. Press Ctrl+Z to exit config mode.
  6. Type 
    wr
    to write the config.

Congrats, you should now be safe from future password lockouts! I managed to save several thousands of dollars in flights and days of wasted time having to go on site and fix this. If this procedure helped you too, please feel free to show some support with PayPal or Bitcoin (bc1ql74yuuxaymlc8c2pmwhdmc28hzp4kr5zjn77k4) / Bitcoin Cash (qr60uckvnv32d8e0k3zdxqplku40lq7fks5qeec4ah). Thanks!