Hello @the_rock. Here you are:
Since around 01.00 PM, tunnel is up, though ping still doesn't work. My colleagues in Australia need to check if they see my incoming ping and maybe firewall rule is missing but traffic is now successfully encrypted in the tunnel. I think the change you proposed here https://community.checkpoint.com/t5/Security-Gateways/Site-to-site-Disconnects-amp-Questions/m-p/175... made the trick. We still have to confirm with colleagues in Australia on Monday. I'll keep you posted.
Thanks a lot guys for your support. This community is incredible
Regards,
Alain