TCP server created in C language not working on internet - tcp

Question

I have created a very simple server program to accept a connection send "Hello World" back to client.I connected to server (localhost) using telnet and it works fine.Now I want to run it over internet and its not working. I tried binding it to my public IP address(search it on google) and it doesn't work.`server_socket=socket(AF_INET,SOCK_STREAM ,0);
serverAddr.sin_family = AF_INET;
serverAddr.sin_port= htons(7892);
serverAddr.sin_addr.s_addr = inet_addr("192.168.43.241");//htonl(INADDR_ANY);//INADDR_ANY;//inet_addr("157.48.97.106");
memset(serverAddr.sin_zero,'\0',sizeof serverAddr.sin_zero);
bind(server_socket, (struct sockaddr *)&serverAddr,sizeof(serverAddr) );
if(listen(server_socket,5)==0)
printf("listening\n");
addr_size=sizeof client_addr;
printf("IP address is: %s\n", inet_ntoa(serverAddr.sin_addr));
while(1)
{
client_socket= accept( server_socket,(struct sockaddr *)&client_addr,&addr_size);
printf("Waiting\n");
printf("client_socket %d\n",client_socket);
int pid=fork();
if(pid>0)
{
printf("PID:%d\n",pid);
dup2(0,client_socket);
}
else
{
dup2(client_socket,0);
printf("%d %d\n",pid,client_socket);
send(client_socket,buffer,strlen(buffer),0);
printf("Message Sent\n");
shutdown(client_socket,0);
close(client_socket);
perror("CLOSE");
printf("Connection Closed\n");
exit(0);
}
}`

Answer 1

In principal you can bind to 0.0.0.0 (which should be the same as the INADDR_ANY that you have in the comment) to listen on all IPv4 addresses. This means you will be able to accept loopback connections as well as connections on all network cards (and thereby from the outside). This should work for you (assuming the remaining program works reliably on loopback).
If you can't connect from outside of the PC on the same network you most likely have a firewall configuration issue. Some OSes by default block incoming connections from the outside if there's no explicit firewall rule that allows it.
If you want to connect from the internet to the PC and you are connected through a router with NAT you also have to configure the router to forward the connection correctly.