[Swan] Trying to connect using libreswan to a Fortigate IPsec VPN

[Paul Wouters]

On Thu, 8 Jul 2021, Dan Stromberg wrote:

> I'm trying to connect to a Fortigate server from a Debian 10.10 host.  I'm seeing no response from the Fortigate server.
> 
> Lots of specifics about the situation are at:
> https://superuser.com/questions/1661309/libreswan-fortigate-ipsec-only-no-ssl-gives-60-second-timeout-exceeded-af

No answer to your first packet is almost always a firewall issue.

If you want, feel free to fire it up against vpn.nohats.ca, which has no
firewall and will always respond to strange IKE messages with an error.

If that shows you the same symptoms, it IS a firewall on or near your end.

Paul