moritz' answer is perfectly good. Here's another in the spirit of TIMTOWTDI. It uses builders instead of defaults. (Slightly slower object construction, but generally considered a cleaner way of doing things in terms of making it easier for subclassing.)

my @ldap_attrs = qw(
   ssl host port retry timeout version
   loginID loginPW logging
);

use constant {
    _build_ssl     => 1,
    _build_port    => 12345,
    _build_timeout => 42,
};

has $_ => (
   is       => "rw",
   reader   => "get_$_",
   writer   => "set_$_",
   required => 0,
   __PACKAGE__->can("_build_$_")
      ? (builder => "_build_$_")
      : (),
) for @ldap_attrs;
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