If you are running this on a *NIX based platform, you should look into the IO::Interface module - This module gives you access to a wealth of information about network interface configurations. For example, from the documentation ...

use IO::Socket;
use IO::Interface qw(:flags);

my $s = IO::Socket::INET->new(Proto => 'udp');
my @interfaces = $s->if_list;

for my $f (@interfaces) {
    print "interface = $if\n";
    my $flags = $s->if_flags($if);
    print "addr =      ",$s->if_addr($if),"\n",
        "broadcast = ",$s->if_broadcast($if),"\n",
        "netmask =   ",$s->if_netmask($if),"\n",
        "dstaddr =   ",$s->if_dstaddr($if),"\n",
        "hwaddr =    ",$s->if_hwaddr($if),"\n";


    print "is running\n"     if $flags & IFF_RUNNING;
    print "is broadcast\n"   if $flags & IFF_BROADCAST;
    print "is p-to-p\n"      if $flags & IFF_POINTOPOINT;
    print "is loopback\n"    if $flags & IFF_LOOPBACK;
    print "is promiscuous\n" if $flags & IFF_PROMISC;
    print "is multicast\n"   if $flags & IFF_MULTICAST;
    print "is notrailers\n"  if $flags & IFF_NOTRAILERS;
    print "is noarp\n"       if $flags & IFF_NOARP;
}
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If all that you are looking for is the MAC address of the interface card, then the $obj->if_hwaddr method is all you will need to worry about.

 

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