C#

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.

C#

//  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.

Chilkat.Dns dns = new Chilkat.Dns();

//  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.
bool 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.