my $ip = "192.168.3.5";
$ip = quotemeta $ip;
my @fwlog;
my $logfile = "/tmp/05jul01.drop";

open LOG, "$logfile" or die "Can't open $logfile: $!\n";
while (<LOG>){
   push @fwlog,$_ if m/\b$ip\b/o;
}
close LOG;
print @fwlog;