UDP and NAT

[Keiji Costantini]

At the moment I have 2 network connected in a VPN and I'm planning to
extend this.

Actual status:
Network A has a public IP
Network B is behind a provider-scale NAT.

Actually I'm using openvpn with a single UDP connection from B to A, and
hosts inside Network A can communicate with B.

I tried with tinc, and I saw tinc has to go TCP-Only for accomplish
this. This is because Tinc can't reutilize incoming UDP connections to
reply back - has to set up an outgoing udp connection defined in config
(thing that in a NAT-ed environment isn't possible)

I saw in git repository that tinc fallbacks to TCP-Only if it can't
estabilish a double-UDP connection, that is fine. But shouldn't tinc get
the ability to use an inbound tcp connection to answer back the remote
host? (maybe setting incoming ip and leaving port blank or something)

-- 
Keiji Costantini