[strongSwan] Setup site-to-site VPN via central server

[Martin Sand]

Ok, I have installed strongswan on my laptop (192.168.2.125) behind 
vpn-second (192.168.2.1) and configured another subnet 192.168.3.0/24 on 
the hub and assigned the virtual IP 192.168.3.1. Established tunnel, 
sSeems to work. So now I simulate the other gateway 500km away.

When I now try to reach the desktop 192.168.2.100 the connection gets 
refused by the vpn-second gateway.

Ping gives the following result:
PING arbeitszimmer (192.168.2.100) 56(84) bytes of data.
 From router-second (192.168.2.1) icmp_seq=1 Destination Port Unreachable

So I added leftfirewall=yes on the vpn-second gateway ipsec.conf. Now it 
works. I hope that solved the problem.

Best regards
Martin