Seems the method of using certificate-based connection won’t work with non-Sophos firewall.
I had to switch to shared-phrase in order to make it work.
Not sure if that problem is due to old firmware/device on the other side or is it compliance issue.
However, I had to go on the VPN settings on both firewalls and make sure all settings at both sides are exactly the same.
Finally, I decided to switch back to pre-shared key instead of the certificate-based authentication between the two appliances.
The moment I set the key on the initiator, the tunle immediatly came up.
Yep, no much result on the web about this subject.
I don’t know what the cause, nor why Sophos didn’t take it seriously.
Anyway, if you’ve downloaded version 16 of Sophos XG virtual appliance for KVM and you got the nice error message of
firstboot failed: swapon /dev/swap
But, if you know and sure you’ve done everything right and as per Sophos documents, then most likely you have the same issue we run through.
For some unclear reason we were able to solve this by having the Hyper-V version of the same appliance and run it on KVM platform
Our team members are testing it now on OpenStack with our service provider to make sure of the compliance.