Just writing down the general recipe as the normal one did not work for Half-Life. We are playing with
This scene release as it includes a lot of coop mods, but any customised HL v46, 1.1.1.0 version should work. Thanks to eclipse for the crosshair sprites, and good old maps. I compiled this
pack of old essentials for a better experience. You know what to do X-Pec!
1. Install
hamachi 1.0.3.0
3. Run: ncpa.cpl -> goto the advanced menu -> advanced settings -> move hamachi to top. Restart.
3. Change hamachi preferences in the window tab, check "Show "Advanced..." peer menu item"
4. Now right click -> advanced on all the users you wish to play with. Leave their VPN peer address alone, but change their VPN peer alias to your ip except you change the last number with the last number in their peer address.
(I.e. say you have ip 5.70.45.192, and one user has 5.241.93.82. Then the peer alias that you should put for him is 5.70.45.82.)
5. Start HL, make one user put up a LAN server, then connect through the console to that peer alias (or more easily, the peer name).
Usually, step 1->2. Suffices for most games that we've encountered so far, but HL is picky.