I recently ran into a situation where I need to have many many raspberry pi's running all over the country and I need to "talk" to them from a central computer to tell them when to run a particular program I have pre-loaded on them. However the people that will be "hosting" them if you will are very very NON-computer savvy people, so I really can't have them configure their routers to set up VNC or the like connections, so I thought, I can solve this with "Sockets" right? :-) So what I want to do is have the pi's talk to my computer and say "I'm on and running, what do you want me to do?" and then I can send back to them what to do. Problem is I can't get the dang things to connect. :-( I have my router set to forward port 7777 to my computer and I have a no-ip service that hosts a name for my router.

But every time the connection times out and won't connect . What am I doing wrong? Here is my code:

Server Code

use IO::Socket::INET;
 
# auto-flush on socket
$| = 1;
 
# creating a listening socket
my $socket = new IO::Socket::INET (
    LocalHost => '127.0.0.1',
    LocalPort => '7777',
    Proto => 'tcp',
    Listen => 5,
    Reuse => 1
);
die "cannot create socket $!\n" unless $socket;
print "server waiting for client connection on port 7777\n";
 
while(1)
{
    # waiting for a new client connection
    my $client_socket = $socket->accept();
 
    # get information about a newly connected client
    my $client_address = $client_socket->peerhost();
    my $client_port = $client_socket->peerport();
    print "connection from $client_address:$client_port\n";
 
    # read up to 1024 characters from the connected client
    my $data = "";
    $client_socket->recv($data, 1024);
    print "received data: $data\n";
 
    # write response data to the connected client
    $data = "ok";
    $client_socket->send($data);
 
    # notify client that response has been sent
    shutdown($client_socket, 1);
}
 
$socket->close();
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Client Code

#!/usr/bin/perl

use IO::Socket::INET;


$| = 1;

my $socket = new IO::Socket::INET (
PeerHost => 'theaddressofmycomputer.com',
PeerPort => '7777',
Proto    => 'tcp',
);
die "Cannot connect to the server $!\n" unless $socket;
print "Connected to the server!\n";

my $req = "Hello World\n";
my $size = $socket->send($req);
print "Sent data of length $size\n";

shutdown($socket, 1);

my $response = "";
$socket->recv($response, 1024);
print "Recieved response: $response\n";

$socket->close();
[download]

OK, I got it working, thank you to everyone for all your help, it was the windows firewall. I simply had to create an inbound and outbound rule allowing communication on the port I want and it worked like a charm!