System > Maintenance > Restart >  Shut down and restart NGAF device

The exact steps to disable the firewall on your M5400 device will depend on the specific model and operating system you are using. However, generally, you can try the following steps:

Log in to your M5400 device as an administrator or with administrative privileges.
Navigate to the "Firewall" or "Security" section of the device's settings.
Look for an option to disable or turn off the firewall. This may be a toggle switch or a checkbox.
If you cannot find an option to disable the firewall, you may need to create a new rule in the firewall settings that allows all traffic to pass through. This will effectively disable the firewall, but it is not recommended for security reasons.
Once you have disabled the firewall or created a rule to allow all traffic, be sure to save your changes.
It's worth noting that disabling your firewall can leave your device vulnerable to security threats, so it's important to only do so temporarily and for specific reasons. If you're having trouble accessing a particular application or service, for example, you may need to create a rule in the firewall settings that allows that specific traffic to pass through rather than disabling the firewall entirely.

press the physical power button for 5 second to shutdown the device

Press the physical power button on the back of the sangfor device

please follow below steps:

Log in to your M5400 device as an administrator or with administrative privileges.

Navigate to the "Firewall" or "Security" section of the device's settings.

Look for an option to disable or turn off the firewall. This may be a toggle switch or a checkbox.
If you cannot find an option to disable the firewall, you may need to create a new rule in the firewall settings that allows all traffic to pass through. This will effectively disable the firewall, but it is not recommended for security reasons.

Once you have disabled the firewall or created a rule to allow all traffic, be sure to save your changes.

Log in to your M5400 device as an administrator or with administrative privileges.
Navigate to the "Firewall" or "Security" section of the device's settings.
Look for an option to disable or turn off the firewall. This may be a toggle switch or a checkbox.
If you cannot find an option to disable the firewall, you may need to create a new rule in the firewall settings that allows all traffic to pass through. This will effectively disable the firewall, but it is not recommended for security reasons.

You can do it via GUI interface or go to management console via console cable and can try some shutdown commands. I search it on google but I dont find any CLI command yet but it 100% sure that these commands exists and we can do it with CLI as well.

There is a physical button on the appliance