my %macs = (
  '00:11:22:33:44:55' => {
    'response_status' => 12,
    'response_date'   => 'yesterday',
  },
  'AA:BB:66:12:13:14' => {
    'response_status' => 0,
    'response_date'   => '2004-12-31',
  },
  # ... and so on
);

##</code><code>##

my $mac = <STDIN>;
chomp $mac;

if ( exists $macs{$mac} )
{
  print "Okay, found mac $mac:\n";
  print "response_status: $macs{$mac}{response_status}\n";
  print "response_date:   $macs{$mac}{response_date}\n";
}
else
{
  print "Sorry, don't recognize that mac\n";
}