FortiGate Next Generation Firewall utilizes purpose-built security processors and threat intelligence security services from FortiGuard labs to deliver top-rated protection and high performance, including encrypted traffic.
This article describes the typical circumstances behind the 'Modem failed to open'.
Scope
FortiGate.
Solution
The sample system event message will be looked like below:
type="event" subtype="system" level="information" vd="root" logdesc="Modem failed to open" msg="modem: unable to open modem device - check hardware"
This message says the 3G/4G modem connected to the FortiGate via the USB slot failed to open. Use the following debug command to check the status of the LTE modem:
diagnose sys lte-modem info
Additional information:
This error message can be an expected behavior and not a bug when the FortiGate has no LTE modem connected to the FortiGate but it was enabled on the CLI.
The error message will keep appearing until the modem is successfully connected OR the configuration is removed.
To avoid this error message being generated unnecessarily and confusing, make sure the following configuration is disabled if it is not being used:
Disabling the modem status.
config system modem
set status disable
end
Remove any firewall address object associated with the modem.
