I tried Vassal for the first time with my newly created module, and via 2 different PCs to see what each player sees of the other’s moves.
Well, it roughly works. However, some information are not transmitted. Why? I don’t know, it seems that 90% of the actions done by the first player are received and displayed by the second player. But what about the 10% remaining?
The 2 PCs have the same IP address, but I guess that this has nothing to do with the problem.
Synchronize seems to work. But I won’t synchronize after every action, right?
If the NICs on the two machines have the same local IP address and are on
the same LAN, then it cannot possibly work correctly. Being NATed behind
the same routable IP address is a completely different thing, as in that
case, the two machines should still have different local IPs.
You should only need to synchronize once, at the start of the game.