I don't know a lot about VPNs but I'd like to connect to a Fortinet VPN with Ubuntu.

I can connect on Windows using Forticlient just by entering the policy server (vpn.theserver.com) and then it asks for a user/password. I use IPSec.

  • 1
    I used strongSwan for connecting to FortiGate from Arch Linux. See this answer for instructions. Feb 16, 2018 at 14:56

2 Answers 2


If you use SSL based VPN from Fortinet, you can use openfortivpn software which is part of Ubuntu and Fedora.

$ sudo apt install -y openfortivpn || yum install -y openfortivpn
$ touch openfortivpn.conf
$ chmod go= openfortivpn.conf

Edit openfortivpn.conf:

host =
port =
username =
password =
# trusted-cert =

Connect the first time:

$ sudo openfortivpn -c openfortivpn.conf
ERROR:  Gateway certificate validation failed, and the certificate digest in not in the local whitelist. If you trust it, rerun with:
ERROR:      --trusted-cert  <some-random-string-to-add-to-trusted-cert>

Edit openfortivpn.conf file and update trusted-cert option with the string from the error. Make sure the option is not commented (remove the #).

Each time you need to connect, run:

sudo openfortivpn -c openfortivpn.conf

You could also do it straight through the command line and make an alias for it in your .bashrc. This is less secure as any user on the system will be able to see the password using ps.

sudo openfortivpn -u <USER> -p <PASSWORD> --trusted-cert <CERTIFICATE> <SERVER>:<PORT>

To disconnect press: Ctrl+C

  • 2
    Worked fine in debian, after compiling operfortivpn from github
    – Damico
    Apr 24, 2019 at 19:25
  • 2
    Worked for me like a charm on AWS Ec2 Ubuntu 18.04 Thank you so much May 23, 2019 at 19:14
  • I always get a "Received bad header from gateway:" error after entering the 2factor authentication token. Guess it's time to secondboot windows sadly...
    – Klesun
    Dec 4, 2019 at 9:20
  • hey, if I want to add the pre-shared key into this config file, how I can do this? Apr 4, 2020 at 16:39
  • Amazing job worked fine on Ubuntu 18.04 without any issue whatsoever
    – Terminator
    Aug 21, 2020 at 22:36

Fortinet is just an IPSEC VPN server - you don't specifically need their client to connect to it. The IPSEC HOWTO details a list of various options you have for setting up a Linux VPN client. There are also a few commercial linux IPSec clients such as Shrewsoft.

  • I found the Shrewsoft client on Linux to be almost as painful as using it on MSWindows - I switched to using vpnc - and never looked back.
    – symcbean
    Oct 10, 2019 at 14:52

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