How to troubleshoot when USG FLEX H is freezing and not responding?

Zyxel_Emily

Scenario:
This article describes troubleshooting steps to take when the USG FLEX H becomes unresponsive.

If the firewall is freezing and both GUI and SSH are inaccessible, connect console cable to the device and open TeraTerm. Serial Port > Baud rate: 115200.

1. Check if console is still working when you enter any commands on console.
   usgflex700h> show version
   usgflex700h> show interface vrf main
2. Ping 8.8.8.8 from device on console and check the result.
   usgflex700h> cmd ping 8.8.8.8
3. Connect one laptop in LAN and ping the device LAN IP. Check if there is any ping loss.
4. Collect diagnostic file.

• Collect diag-info BEFORE you restart the device manually.
  Note: if diag-info cannot be collected before restarting, use "send break +x" BEFORE restarting the device manually.
  For example, click "Send break" on TeraTerm and then enter "x"

• Restart the device manually.
• Collect diag-info AGAIN after the device boots up. You can collect the diagnostic file on GUI or CLI.

Collect diagnostic file on GUI

Collect diagnostic file using CLI

https://community.zyxel.com/en/discussion/18683/how-to-collect-diag-info-in-cli-mode