Dart

Use Public DNS Servers (Google and Cloudfare)

See more DNS Examples

Demonstrates how to use Google and Cloudfare nameservers for all DNS lookups within Chilkat.

Note: This example requires Chilkat v9.5.0.96 or later.

Dart

import 'package:chilkat/chilkat.dart';

void main() {
  // The new Chilkat DNS class is a singleton that allows an applicaton to select 
  // the DNS nameservers used throughout Chilkat.

  // "singleton" means that all Chilkat DNS object instances work with a single
  // copy of internal DNS settings that are application wide.

  // Chilkat does DNS lookups internally whenever a domain name is passed to a Chilkat method, or when the domain
  // name is part of a URL passed to a Chilkat method.  It could be in HTTP, Ftp2, SSH, IMAP, Socket, etc.

  // This exampel will show how to use the Cloudfare and Google DNS servers.
  // 
  // Google Public DNS:
  //   - Primary DNS: 8.8.8.8
  //   - Secondary DNS: 8.8.4.4
  //   Google Public DNS is known for its speed and reliability. It's operated by Google and is widely used by many internet users.

  // Cloudfare Public DNS:
  //   - Primary DNS: 1.1.1.1
  //   - Secondary DNS: 1.0.0.1
  //   Cloudfare Public DNS is also known for its speed and reliability, and is also widely used.

  final dns = CkDns();

  // Indicate our TLS preference:
  // 0: No TLS
  // 1: Prefer TLS if possible
  // 2: Require TLS
  dns.tlsPref = 0;

  // If you choose "No TLS", then all DNS requests will use UDP, or TCP for those requests with large responses.
  // Choosing "No TLS" provides the fastest DNS lookups, and is generally what you're already doing.

  // If you choose "Prefer TLS if possible", then Chilkat will use DNS over TLS for those nameservers that
  // support TLS.

  // If you choose "Require TLS", then Chilkat will ignore nameservers that don't support TLS,
  // and all DNS communications will occur over private and secure TLS connections.

  // When you specify a nameserver to be used, you'll tell Chilkat whether it supports DNS or not.
  // Here' we're setting the nameservers to Google and Cloudfare.
  // They both support TLS, but since we set our TLS preference = 0, Chilkat will not use TLS.
  // (If we set our TLS preference equal to 1 or 2, then Chilkat will use TLS for Google and Cloudfare DNS.)

  // First, make sure we remove all existing nameservers.
  dns.removeAllNameservers();

  // Add the Google and Cloudfare nameservers.
  final supportsTls = true;
  dns.addNameserver('1.1.1.1', supportsTls);
  dns.addNameserver('8.8.8.8', supportsTls);
  dns.addNameserver('1.0.0.1', supportsTls);
  dns.addNameserver('8.8.4.4', supportsTls);

  // That's it.  Now all DNS lookups in Chilkat will use the above nameservers.
}