diff --git a/server/game-group.js b/server/game-group.js
index ca64436b..5d646e42 100644
--- a/server/game-group.js
+++ b/server/game-group.js
@@ -181,8 +181,8 @@ GameGroup.prototype.getNumPlayers = function() {
   }, 0);
 };
 
-GameGroup.prototype.controllerUrl = function() {
-  return this.games.length > 0 ? this.games[0].controllerUrl : undefined;
+GameGroup.prototype.getControllerUrl = function(baseUrl) {
+  return this.games.length > 0 ? this.games[0].getControllerUrl(baseUrl) : undefined;
 };
 
 GameGroup.prototype.sendQuit = function() {
diff --git a/server/game.js b/server/game.js
index cff12e36..538a6c4f 100644
--- a/server/game.js
+++ b/server/game.js
@@ -36,7 +36,6 @@ var hftSite      = require('./hftsite');
 
 /**
  * @typedef {object} Game~Options
- * @property {string} baseUrl the base url used to make urls
  */
 
 /**
@@ -57,13 +56,14 @@ var Game = function(id, gameGroup, options) {
   this.numPlayers = 0;
   this.sendQueue = [];
   this.options = options;
-  if (this.runtimeInfo) {
-    this.controllerUrl = options.baseUrl + "/games/" + this.runtimeInfo.info.happyFunTimes.gameId + "/index.html";
-  }
   this.setGameId();
   debug("create game " + this.  gameId);
 };
 
+Game.prototype.getControllerUrl = function(baseUrl) {
+  return this.runtimeInfo ? baseUrl + "/games/" + this.runtimeInfo.info.happyFunTimes.gameId + "/index.html" : undefined;
+};
+
 Game.prototype.setGameId = function() {
   this.gameId = (this.runtimeInfo ? this.runtimeInfo.info.happyFunTimes.gameId : "") + " id=" + this.id;
 };
diff --git a/server/hft-server.js b/server/hft-server.js
index fd3ebd3f..d72c4d16 100644
--- a/server/hft-server.js
+++ b/server/hft-server.js
@@ -47,6 +47,7 @@ var HFTGame                   = require('./hftgame');
 var hftSite                   = require('./hftsite');
 var highResClock              = require('../lib/highresclock');
 var http                      = require('http');
+var iputils                   = require('../lib/iputils');
 var log                       = require('../lib/log');
 var mime                      = require('mime');
 var NonRequire                = require('./non-require');
@@ -99,6 +100,34 @@ var HFTServer = function(options, startedCallback) {
     g[prop] = options[prop];
   });
 
+  var updateIpAddress = function(address) {
+    if (relayServer) {
+      relayServer.setOptions({baseUrl: getBaseUrl()});
+    }
+    hftSite.setup({address: address});
+    if (appleCaptivePortalHandler) {
+      appleCaptivePortalHandler.setOptions({address: address});
+    }
+  };
+
+  var getAddress = (function() {
+    var oldAddress;
+
+    return function() {
+      var address = g.address || iputils.getOneIpAddress();
+      if (address !== oldAddress) {
+        oldAddress = address;
+        console.log("using ip address: " + address);
+        updateIpAddress(address);
+      }
+      return address;
+    };
+  }());
+
+  var getBaseUrl = function() {
+    return "http://" + getAddress() + ":" + g.port;
+  };
+
   g.gameDB = g.gameDB || new AvailableGames();
 
   var eventEmitter = new events.EventEmitter();
@@ -111,7 +140,11 @@ var HFTServer = function(options, startedCallback) {
   var app = express();
   var relayServer;
 
-  hftSite.setup(g);
+  hftSite.setup({
+    address: getAddress(),
+    port: g.port,
+    privateServer: g.privateServer,
+  });
 
   g.cwd = path.normalize(path.join(__dirname, ".."));
 
@@ -308,7 +341,7 @@ var HFTServer = function(options, startedCallback) {
 
   var appleCaptivePortalHandler = new AppleCaptivePortalHandler({
     baseDir: path.join(g.cwd, g.baseDir),
-    address: g.address,
+    address: getAddress(),
     port: g.port,
     sendFileFn: sendFileResponse,
   });
@@ -377,7 +410,7 @@ var HFTServer = function(options, startedCallback) {
     }
     var prepFn = isTemplate ? (function() {
       var params = [{
-        localhost: g.address,
+        localhost: getAddress(),
       }];
       if (runtimeInfo) {
         params.push(runtimeInfo);
@@ -521,8 +554,7 @@ var HFTServer = function(options, startedCallback) {
       }
       var RelayServer = require('./relayserver.js');
       relayServer = options.relayServer || new RelayServer(servers, {
-        address: g.address,
-        baseUrl: "http://" + g.address + ":" + g.port,
+        baseUrl: getBaseUrl(),
         noMessageTimout: options.inactivityTimeout,
         gameDB: g.gameDB,
       });
diff --git a/server/relayserver.js b/server/relayserver.js
index 7c1d10f0..0a15142e 100644
--- a/server/relayserver.js
+++ b/server/relayserver.js
@@ -45,9 +45,6 @@ var WSServer     = require('./websocketserver');
  * RelayServer options
  * @typedef {Object} RelayServer~Options
  * @property {AvailableGames} gameDB The game db
- * @property {String} address - address that will
- *         replace "localhost" when a game's controllerUrl is
- *         passed in.
  * @property {String?} baseUrl ???
  * @property {WebSocketServer?} WebSocketServer constructor for WebSocketServer (for testing)
  */
@@ -79,10 +76,22 @@ var RelayServer = function(servers, options) {
   var g_nextSessionId = 0;
   var g_gameGroups = {};
   var g_numGameGroups = 0;
+  var g_options = {};
   var socketServers = [];
   var eventEmitter = new events.EventEmitter();
   var gameDB = options.gameDB;
 
+  this.setOptions = function(options) {
+    ["baseUrl"].forEach(function(key) {
+      var value = options[key];
+      if (value !== undefined) {
+        g_options[key] = value;
+      }
+    });
+  };
+
+  this.setOptions(options);
+
   this.on = eventEmitter.on.bind(eventEmitter);
   this.addListener = this.on;
   this.removeListener = eventEmitter.removeListener.bind(eventEmitter);
@@ -130,7 +139,7 @@ var RelayServer = function(servers, options) {
     }
     var gameGroup = g_gameGroups[gameId];
     if (!gameGroup && makeGroup) {
-      gameGroup = new GameGroup(gameId, this, { gameDB: gameDB, baseUrl: options.baseUrl });
+      gameGroup = new GameGroup(gameId, this, { gameDB: gameDB });
       g_gameGroups[gameId] = gameGroup;
       ++g_numGameGroups;
       debug("added game group: " + gameId + ", num game groups = " + g_numGameGroups);
@@ -161,7 +170,7 @@ var RelayServer = function(servers, options) {
           gameId: id,
           serverName: computerName.get().trim(),
           numPlayers: gameGroup.getNumPlayers(),
-          controllerUrl: gameGroup.controllerUrl(),
+          controllerUrl: gameGroup.getControllerUrl(g_options.baseUrl),
           runtimeInfo: gameGroup.runtimeInfo,
         });
       }