public function setLocalDomain($domain)
    {
        if ('[' !== substr($domain, 0, 1)) {
            if (filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4)) {
                $domain = '['.$domain.']';
            } elseif (filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
                $domain = '[IPv6:'.$domain.']';
            }
        }

        $this->domain = $domain;

        return $this;
    }