How to check modem status

How to check modem status

Sometimes the modem may not work properly, or the unit may not be detecting the modem. Use the following diagnostic commands to help you troubleshoot issues with the modem.

diagnose sys modem {cmd | com | detect | history | external-modem| query| reset}


You should always run the following diagnose command after inserting the USB modem into the unit:

diagnose sys modem detect


You can view the modem configuration by using the get system modem command. You can also view the modem’s vendor identification as well as the custom product identification number from the information output from the get system modem command.


When there are connectivity issues, use the following to help you resolve them:

  • diag debug enable – activates the debug on the console
  • diag debug application modemd – dumps communication between the modem and the unit.
  • diag debug application ppp – dumps the PPP negotiating messages.
  • execute modem dial – displays modem debug output.

The modem diagnose output should not contain any error on the way to initializing. You should also verify the number that is used to dial with your ISP.

This entry was posted in FortiOS, FortiOS 5.4 Handbook, How To and tagged , on by .

About Mike

Michael Pruett, CISSP has a wide range of cyber-security and network engineering expertise. The plethora of vendors that resell hardware but have zero engineering knowledge resulting in the wrong hardware or configuration being deployed is a major pet peeve of Michael's. This site was started in an effort to spread information while providing the option of quality consulting services at a much lower price than Fortinet Professional Services. Owns PacketLlama.Com (Fortinet Hardware Sales) and Office Of The CISO, LLC (Cybersecurity consulting firm).

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