Forticlient: SSL VPN timeout

vpn

I'm using Forticlient to connect to a customer's VPN. It used to work on my MacOS, but it suddendly stopped with apparently no reason. After that I never managed to make it work again on my computer, even it it connects fine with every other device I try (Android, Linux, Windows, another MacOS).

I tried uninstalling and reinstalling several times, but it still fails to connect. I tried removing every single file accessed by the app (checking with lsof) but still fails. Enabling debug I found the following:

20170720 08:27:22.523 [sslvpn:INFO] unknown:0 current uid: 0
20170720 08:27:22.525 [sslvpn:INFO] unknown:0 get current proxy auto config settings
20170720 08:27:22.530 [sslvpn:INFO] unknown:0 use tty:/dev/ttys006
20170720 08:27:22.533 [sslvpn:INFO] unknown:0 connecting to 1.2.3.4:10443 - 10443
20170720 08:27:22.533 [sslvpn:DEBG] unknown:0 tcp connect 1.2.3.4:10443 timeout -1
20170720 08:27:22.542 [sslvpn:INFO] unknown:0 shuting down the running tunnel
20170720 08:27:22.542 [sslvpn:INFO] unknown:0 the tunnel is shut down 
20170720 08:27:22.542 [sslvpn:EROR] unknown:0 connect failed
20170720 08:27:22.542 [sslvpn:INFO] unknown:0 tunnel shutdown -2
20170720 08:27:22.543 [sslvpn:INFO] unknown:0 sslvpn starts to clean up
20170720 08:27:22.547 [sslvpn:INFO] unknown:0 sslvpnd terminated

How's possible it returns timeout right after trying to connect?

I have no firewall enabled on the Mac (10.12.5), I just installed some objective-see apps but none should interfere with network connections.

What else can I check to understand why the connection returns timeout?

Best Answer

Happened to be a change I did to /etc/ppp/options to disable IPSec for another native VPN I had.

I added

plugin L2TP.ppp
l2tpnoipsec 

to connecto to a L2TP/IPSec VPN with only L2TP, but with this change FortiClient SSL VPN stopped working.

Commenting out the two lines restored VPN functionality.