apt install barrier (on main and client)
or snap install barrier
SERVER
on Main computer (controller)
Barrier > Settings (check on Enable SSL, Require client cert, can leave port 24800)
create SSL
start BarrierÂ
CLIENT
Barrier > Settings (check on Enable SSL, Require client cert, run same SSL commands as above
check on checkbox for Client, enter the Server IP from above into Server IP field
start service