$ perl -E '
say join q{.}, map { int rand 256 } 1 .. 4
   for 1 .. 1500;' > spw1112250.dat
$

##</code><code>##

use strict;
use warnings;

use 5.014;

use Time::HiRes qw{ gettimeofday tv_interval };
my $startTV = [ gettimeofday() ];

my $inFile = q{spw1112250.dat};
open my $inFH, q{<}, $inFile
   or die qq{open: < $inFile: $!\n};
my @lines = <$inFH>;
close $inFH
   or die qq{close: < $inFile: $!\n};

s{\.\d+$}{} for @lines;

my %lookupIPs;
@lookupIPs{ @lines } = ( 1 ) x @lines;

my $lookFor = q{17.23.213};
say
   qq{$lookFor },
   $lookupIPs{ $lookFor } ? q{} : q{not },
   qq{found in $inFile};

say qq{Process took @{ [ tv_interval( $startTV, [ gettimeofday() ] ) ] } seconds};

##</code><code>##

17.23.213 not found in spw1112250.dat
Process took 0.002678 seconds