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Chuuung
Chuuung
Explorer
March 16, 2022
Question

Can't connect to fortigate console via rs232

  • March 16, 2022
  • 3 replies
  • 4422 views

I recently got fortigate 3140b on market, and first i tried to connect with management port(lan) but it not worked (maybe ex-admin changed it?) so next i tried to connect with rs232 console port with putty (

9600 8N1 No Flow Control) and it shows text well(like bootup bios message, login message) but the tx (which i press on keyboard) not sends well. if i type 'a' to keyboard, i must enter 'a' more than 5 times and eventually i can't access it. i asked seller if he changed serial settings but he says he doesn't know.

 

How can i access this fortigate? or reset it?

3 replies

AlexC-FTNT
Staff
AlexC-FTNT
Staff
March 16, 2022

Ideally, the first thing to do after such a purchase is a clean install (format Boot device, install new firmware). You can also try to run a hardware test, maybe the unit is damaged.

    Chuuung
    ChuuungAuthor
    Explorer
    March 16, 2022

    i really want to format this device, but without accessing cli it's impossible to do that .. maybe serial hardware damaged?

    ede_pfau
    SuperUser
    ede_pfau
    SuperUser
    March 16, 2022

    Maybe you should try all available serial speed settings

     

    9600, 19200, 38400, 57600, 115200

     

    to be able to access the boot menu. There, you can set the serial transmission parameters. Note that they will only take effect after rebooting.

    * https://community.fortinet.com/t5/FortiGate/Technical-Tip-How-to-change-the-baud-rate-of-the-FortiGate/ta-p/192413

     

    I wonder if you can get access using the default credentials then...

      Chuuung
      ChuuungAuthor
      Explorer
      March 16, 2022

      actually i pressed keyboard many-many times and successfully changed baudrate in bios to 9600, but same issues

      AlexC-FTNT
      Staff
      AlexC-FTNT
      Staff
      March 16, 2022

      Have you tried to leave the unit powered on for 10-20min before connecting to the console? Maybe it needs time to load up everything, as it is quite a big and slow device.

       

      If you know the status of the unit or have the previous configuration, you can try to connect via SSH to one of its regular ports (where SSH is allowed). In this case you need the logon information. From there, you can check the flash, boot from another partition, or even remove some of the configuration. 
      The console port should not be slow as you mention, but if there's a hardware failure, I doubt it is related to the port itself, so you may experience other strange behaviors.

       

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