I've posted this in other places as a suggestion, take a look at www.smartfoxserver.com You can build the game logic on the server side and you get a ton of useful features for match-making, managing rooms, users, chats, banning and whatnot. The whole thing is for free to start with a max of 100CCU and pretty affordable if you want to scale up. For pricing check their elastic licenses, they are the most affordable, imho.
@justtime: Technically, you can use pretty much any networking solution. The game itself is turn based and thus not very demanding. If you want Voice communication and or want to synchronize head and hand movement (in a VR Poker), you can use any solution that supports "realtime" networking. To make a useful suggestion, let us know more or ask questions about the options discussed in (many) threads here (example).
As already mentioned, you can use pretty much anything. If you'd state what kind of networking features you need then you might get more specific answers. For example you'll probably get different recommendations for a LAN only poker game than you would an internet game with a public lobby system or automatic match maker.