In this page you setup a tunnel to allow VPN traffic
through your firewall machine.
ID (unique). The unique identifier for this tunnel. It is
highly recommended to leave this value unchanged.
Type. The tunnel type. "ipsec" for an IPSec tunnel (the
default and recommended setting); "ipip" for an IPIP
tunnel.
Zone. The zone from/to where VPN traffic will flow using this
tunnel. For the kind of VPN we are setting here, this must be set
to "wan" (the Internet zone).
Gateway IP. The IP address of the "remote" gateway machine.
Set this to 0.0.0.0/0, meaning that VPN traffic is going to be
allowed from anywhere on the Internet, if the remote end has
neither a fixed IP address nor a permanent connection to the
Internet.
Gateway Zone (optionnal). Set it to "vpn" because the VPN
will be the "gateway" between both private networks.
Then, press the Next button to add the firewall tunnel
for VPN traffic and press Apply on the Tunnels page to make your
changes effective.