In order to play older games, like Red Alert, via LAN connections on newer operating systems you'll need to emulate IPX connections between the machines. ThereThere are a few ways to accomplish this.
For dosDOS games you're in luck as DosBox comes with this support natively. SimplySimply start the ipx server on one machine ipxnet startserver [UDP port]
and then connect to it on the rest of the machines ipxnet connect <IP> [UDP port]
For windowsWindows based games you can use something like Kali which will give you a fairly robust interface, or something like ipxemu or ipxwrapperipxwrapper which will trick the games into thinking they are connected via IPX.