use strict;
use warnings;

my @allIpsList = qw(10.1.1.10 10.1.1.17 10.1.1.125);
my %ipsMatch = map {$_ => 1} @allIpsList;

my $testFile = <<TESTDATA;
10.1.1.17
10.1.1.23
10.1.1.79
10.1.1.125
TESTDATA

open my $fh, '<', \$testFile;
my @found = check_fw_logs (\%ipsMatch, $fh);

print "@found\n";


sub check_fw_logs {
    my ($ipsMatch, $fh) = @_;
    my @matched;

    while (defined (my $line = <$fh>)) {
        next if $line !~ /(\d+\.\d+\.\d+\.\d+)/;
        push @matched, $1 if exists $ipsMatch->{$1};
    }

    return @matched;
}

##</code><code>##

10.1.1.17 10.1.1.125