So I've just started working with networking in perl and I'm not quite sure how it works. Here's what I have so far:

use strict;
use warnings;
use IO::Socket;

# Create Socket for recieving messages
my $sockIn = new IO::Socket::INET (
		#LocalAddr => 'xx.xxx.xxx.xxx',
		LocalPort => '7070',
		Proto => 'tcp',
		Listen => 1,
		Reuse => 1,
	)
	or die "Could not create socket: $!\n";

# Listen for messages
my $new_sock = $sockIn->accept();
while(<$new_sock>) {
	print $_;
}
close($sockIn);
print "SockIn Closed.\n";

# Create Socket for sending messages
my $sockOut = new IO::Socket::INET (
		PeerAddr => '10.0.2.15',
		PeerPort => '7070',
		Proto => 'tcp',
	)
	or die "Could not create socket: $!\n";

#Send message
print $sockOut "I'm well.\n";
close($sockOut);
print "Done\n";

use strict;
use warnings;
use IO::Socket;

# Create Socket for sending messages
my $sockOut = new IO::Socket::INET (
		PeerAddr => '192.168.1.15',
		PeerPort => '7070',
		Proto => 'tcp',
	)
	or die "Could not create socket: $!\n";

# Send messages
print $sockOut "Hello there!\n";
sleep 1;
print $sockOut "How are you?\n";
close($sockOut);

print "SockOut Closed.\n";

# Create Socket for receiving messages
my $sockIn = new IO::Socket::INET (
		#LocalAddr => 'xx.xxx.xxx.xxx',
		LocalPort => '7070',
		Proto => 'tcp',
		Listen => 1,
		Reuse => 1,
	)
	or die "Could not create socket: $!\n";

print"SockIn Created.\n";

# Listen for messages
my $new_sock = $sockIn->accept();
while(<$new_sock>) {
	print $_;
}
close($sockIn);

print "Done\n";

So computer one runs the first code - It creates a socket that listens and sends a message back after it receives a message. Computer two does the opposite (runs the second code), it sends a message and then listens for a response.

Here's the output:

Hello there!
How are you?
SockIn Closed.
Could not create socket: Unknown Error

SockOut Closed.
SockIn Created.

Computer two is a virtual machine running CentOS; ifconfig shows that the ip is 10.0.2.15, but it doesn't seem to want to connect.
Any help is appreciated.

This post has been edited by Ed_Bighead: 23 Jun, 2009 - 04:32 AM

I'm not in a position to test run your code at the moment, but it looks to me like comp1 may be attempting to connect to comp2 before comp2 has created its receiving socket. Have you tried having comp1 sleep for a couple seconds after it closes SockIn and before it opens SockOut?

Also, have you verified that comp1 knows how to route to 10.x.x.x? If comp2 is multi-homed or behind a NAT router, comp1 may be seeing it at a different address. (If NAT is the culprit, you'll need to set up port forwarding on the router to get this to work...) Try having comp1 print out the remote IP address after the $sockIn->accept so that you'll know what IP address it sees at the other end of the connection.

That's certainly possible, I'll try sleeping like you suggested. Also, what is the command / syntax to get the IP address that comp1 is seeing?

EDIT:
I'm pretty sure the problem is that the ip address is invalid - when comp1 tries to create the socket to send a message back, it fails and gives me the error above - Could not create socket: Unknown Error.

This post has been edited by Ed_Bighead: 25 Jun, 2009 - 06:20 AM

According to The IO::Socket documentation:

So $new_sock->connected should tell you the IP address it's connected to.