diff --git a/main.cpp b/main.cpp
index 986e16f..aec6c30 100644
--- a/main.cpp
+++ b/main.cpp
@@ -4,6 +4,7 @@
 #include "raylib-cpp/raylib-cpp.hpp"
 #include "paddle.hpp"
 #include "ball.hpp"
+#include "easysock.hpp"
 #include "math-helpers.hpp"
 #include "connect-helpers.hpp"
 #include "client.hpp"
@@ -20,6 +21,7 @@ const float BASE_BOUNCE_DEG = 60;
 const float BASE_BOUNCE_RAD = (BASE_BOUNCE_DEG / 180.0) * M_PI;
 const float BASE_SPEED_COMPONENTS = 18;
 const float BASE_SPEED = sqrt(powf(BASE_SPEED_COMPONENTS, 2) * 2);
+typedef enum {M_SINGLE, M_CLIENT, M_SERVER} Mode;
 
 raylib::Vector2 changeVelocityAfterCollision(Paddle paddle, Ball ball) {
 	float paddle_mid_y = (paddle.getRect().y + paddle.getRect().GetHeight()) / 2.0; /* Middle y value of rectangle */
@@ -44,14 +46,15 @@ raylib::Vector2 changeVelocityAfterCollision(Paddle paddle, Ball ball) {
 /* This function checks the command-line arguments passed to the program.
 It then decides whether the game is in Server or Client mode (or neither), and
 instantiates the appropriate object. The (uninitialized) objects are passed to the
-function as pointers. */
+function as pointers. It returns an enum that indicates whether the game is in server,
+client or single player mode.*/
 
-void check_server_client(int argc, char** argv, Server* server, Client* client) {
+Mode check_server_client(int argc, char** argv, Server* server, Client* client) {
 	std::string connect_code;
 	std::vector<std::string> addr_port; /* Vector to store (IPv4) address and port */
 
 	if (argc < 2) { /* Game was not started in client or server mode */
-		return;
+		return M_SINGLE;
 	}
 
 	/* GAME STARTED IN CLIENT MODE */
@@ -63,6 +66,7 @@ void check_server_client(int argc, char** argv, Server* server, Client* client)
 		addr_port = connect_code::decode(connect_code);
 		try {
 			client = new Client(4, 'T', addr_port[0].data(), std::stoi(addr_port[1]));
+			return M_CLIENT;
 		} catch (int e) {
 			throw;
 		} catch (std::exception& e) {
@@ -90,10 +94,16 @@ void check_server_client(int argc, char** argv, Server* server, Client* client)
 			port = std::stoi(std::string(argv[3]));
 		}
 
+		/* Check if IP is valid */
+		if (check_ip_ver(addr.data()) < 0) {
+			throw EXCEPT_INVALIDARGS;
+		}
+
 		std::string code = connect_code::encode(addr, std::to_string(port));
 		std::cout << "Your code is " << code << std::endl;
 		try {
 			server = new Server(4, 'T', addr.data(), port);
+			return M_SERVER;
 		} catch (int e) {
 			throw;
 		}
@@ -106,23 +116,25 @@ void check_server_client(int argc, char** argv, Server* server, Client* client)
 		throw EXCEPT_INVALIDARGS;
 	}
 
-	return;
-
 }
 
 int main(int argc, char** argv) {
 	/* Check if game was started in server or client mode, and set appropriate variables */
+
+	/* mode - M_CLIENT for client, M_SERVER for SERVER and M_SINGLE for single-player */
+	Mode mode;
+
 	Server server;
 	Client client;
 	try {
-		check_server_client(argc, argv, &server, &client);
+		mode = check_server_client(argc, argv, &server, &client);
 	} catch(int e) {
 		if (e == EXCEPT_TOOFEWARGS) {
 			std::cout << "Started in client mode, but no address was specified." << std::endl;
 			return -1;
 		}
 		if (e == EXCEPT_INVALIDARGS) {
-			std::cout << "Invalid argument. Optional arguments are -S for server mode, or -C for client mode." << std::endl;
+			std::cout << "Invalid argument.." << std::endl;
 			return -2;
 		}
 		if (e == EXCEPT_CONNREFUSED) {