I was just wondering about this too on my new vps, I have 4 ip's for it.
On mumble, there's a setting for "Only respond from this ip:" so I can have one ip for mumble. I just don't know of a way to have paintball only connect with 1 ip.
*The only thing that I thought of, but don't know if it's possible to do, is to have a specific linux user only able to use 1 ip, but I don't know linux well enough to know if I can bind an ip to only one user. Any thoughts?