I have two scripts for sending out UDP packets to IPv4 and IPv6 sockets, using IO::Socket::INET and INET6 respectively.

IPv4 Client

use IO::Socket;
use Socket;

my $sock = IO::Socket::INET->new(
    Proto    => 'udp',
) or die "Could not create socket: $!\n";

my $pack = pack_sockaddr_in(23456, inet_aton('10.254.83.40'));

IO::Socket::send($sock, "message", 0, $pack) or die "Can't send: $!\n"
+;

print $sock->sockhost(),"\n";
print $sock->sockport(),"\n";
print $sock->peerhost(),"\n";
print $sock->peerport(),"\n";
[download]

IPv6 Client

use IO::Socket::INET6;
use Socket;
use Socket6;

my $sock = IO::Socket::INET6->new(
    Proto    => 'udp',
) or die "Could not create socket: $!\n";

my $pack = pack_sockaddr_in6(23456, inet_pton(AF_INET6,'2000:1234:5678
+:9abc::eeff'));

IO::Socket::send($sock, "message", 0, $pack) or die "Can't send: $!\n"
+;

print $sock->sockhost(),"\n";
print $sock->sockport(),"\n";
print $sock->peerhost(),"\n";
print $sock->peerport(),"\n";
[download]

IPv4 Output

0.0.0.0
32807
10.254.83.40
23456
[download]

IPv6 Output

::
-4622771466457284569
2000:1234:5678:9abc::eeff
-4622771466457293920
[download]

Question

I can't figure out why INET6 sockets are printing such weird values for the port numbers, even though I'm using the same 23456 in both cases.