Server::Configuration::ServerFactoryContext& factory_context) {

  const auto& ip_config = MessageUtil::downcastAndValidate<

      const envoy::extensions::matching::input_matchers::ip::v3::Ip&>(

      config, factory_context.messageValidationVisitor());

  const auto& cidr_ranges = ip_config.cidr_ranges();

  std::vector<Network::Address::CidrRange> ranges;

  ranges.reserve(cidr_ranges.size());

  for (const auto& cidr_range : cidr_ranges) {

    const std::string& address = cidr_range.address_prefix();

    const uint32_t prefix_len = cidr_range.prefix_len().value();

    const auto range = THROW_OR_RETURN_VALUE(

        Network::Address::CidrRange::create(address, prefix_len), Network::Address::CidrRange);

    ranges.emplace_back(std::move(range));

  }

  const std::string& stat_prefix = ip_config.stat_prefix();

  Stats::Scope& scope = factory_context.scope();

  return [ranges, stat_prefix, &scope]() {

    return std::make_unique<Matcher>(ranges, stat_prefix, scope);

  };

}