use strict;
use warnings;

use Socket;

my @lines = split m{(?<=\n)}, <<EOD;
ows301.dom.com, 10.157.118.42,
oem300.dom.com, 10.157.124.58,
omo300.dom.com, 10.157.124.58,
pwd302.dom.com, 10.157.126.58,
pwd302.dom.com, 10.157.126.58,
pwd302.dom.com, 10.157.126.58,
pwd302.dom.com, 10.157.126.58,
pwd302.dom.com, 10.157.126.58,
EOD

print do {
   my %seen;
   map  { $_->[ 0 ] }
   sort { $a->[ 2 ] cmp $b->[ 2 ] || $a->[ 1 ] cmp $b->[ 1 ] }
   map  {
        my @flds = split m{,\s*};
        [ $_, $flds[ 0 ], inet_aton( $flds[ 1 ] ) ]
        }
   grep { not $seen{ $_ } ++ }
   @lines
   };

##</code><code>##

ows301.dom.com, 10.157.118.42,
oem300.dom.com, 10.157.124.58,
omo300.dom.com, 10.157.124.58,
pwd302.dom.com, 10.157.126.58,