use Modern::Perl;

my %seen;

while( <DATA> ) {
    chomp;
    $seen{$_}++;
}

my @top = ( sort { $seen{$b} <=> $seen{$a} } keys %seen )[0,1];

foreach ( @top ) {
	say "$_ $seen{$_}";
}

__DATA__
1.1.1.1
2.2.2.2
1.1.1.1
4.4.4.4
1.1.1.1
4.4.4.4