I am on Windows and using Strawberry Perl, and I also have a Windows virtual machine (VM) installed on my machine. The VM creates a network interface with the description "VirtualBox Host-Only Ethernet Adapter", and its IPv4 is: 192.168.56.1 (I configured the VM's network to run in bridge adapter mode, so the VM has an Ethernet interface at address 192.168.1.12). Normally, I use a wireless interface with an IPv4 address at 192.168.1.6.

I want to broadcast in the local subnet. So I ran this code:

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

my $broadcast_address = '255.255.255.255';

my $socket = IO::Socket::INET->new(
    Proto => 'udp',
    Broadcast => 1,
    LocalPort => 8888,
    PeerAddr => $broadcast_address,
    PeerPort => 9999,
) or die "Could not create socket: $!\n";

my $message = "Broadcast message!";
$socket->send($message) or die "Send error: $IO::Socket::errstr\n";

my $hostAddr = $socket->sockhost();
my $hostPort = $socket->sockport();
print "Broadcast message sent from address $hostAddr:$hostPort\n";

$socket->close();

[download]

The problem is it printed this out: "Broadcast message sent from address 192.168.56.1:8888".. The receiver couldn't receive the broadcast message from 192.168.56.1 address, but if I changed the $broadcast_address to 192.168.1.255, it would work.

I diagnosed that the Perl module automatically chooses 192.168.56.1 as the main IP address and then uses it to send messages. How do I get rid of that? And how to make the wireless interface the chosen?

Thanks in advance.

In reply to Broadcast when host machine contains virtual interface by Anonymous Monk

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