output: 
re1  ->  172.28.17.130
re2  ->  17.

------------------------------------------

my $Raw_Log = "";
my $re_ipv4 = qr/(([2]([0-4][0-9]|[5][0-5])|[0-1]?[0-9]?[0-9])[.]){3}(([2]([0-4][0-9]|[5][0-5])|[0-1]?[0-9]?[0-9]))/;
# Open file to read lines
my $logfile = $ARGV[0];
my $linenum = 0;

open(LOGFILEHD, $logfile);

while( <LOGFILEHD>){
   $Raw_Log = $_;
   print "$Raw_Log\n";
   $Raw_Log =~ /($re_ipv4).*($re_ipv4)/;

   print "re1  ->  $1\n";
   print "re2  ->  $2\n";

   $linenum  += 1;
}
close(LOGFILEHD);