SQL Server

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.

SQL Server

--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    --  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.

    DECLARE @dns int
    EXEC @hr = sp_OACreate 'Chilkat.Dns', @dns OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    --  Indicate our TLS preference:
    --  0: No TLS
    --  1: Prefer TLS if possible
    --  2: Require TLS
    EXEC sp_OASetProperty @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.
    EXEC sp_OAMethod @dns, 'RemoveAllNameservers', NULL

    --  Add the Google and Cloudfare nameservers.
    DECLARE @supportsTls int
    SELECT @supportsTls = 1
    EXEC sp_OAMethod @dns, 'AddNameserver', NULL, '1.1.1.1', @supportsTls
    EXEC sp_OAMethod @dns, 'AddNameserver', NULL, '8.8.8.8', @supportsTls
    EXEC sp_OAMethod @dns, 'AddNameserver', NULL, '1.0.0.1', @supportsTls
    EXEC sp_OAMethod @dns, 'AddNameserver', NULL, '8.8.4.4', @supportsTls

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

    EXEC @hr = sp_OADestroy @dns


END
GO