Google GSuite Toolbox - Goolges DIG Tool

    Goolge GSuite Tools checks your name servers, A records, mail servers, SOA records for errors, consistency, accuracy and speed using several DNS tests. You can also flush your domain from Google's Recursive DNS Servers.
SolveDNS.com - SolveDNS is a great tool for troubleshooting DNS problems
    SolveDNS checks your name servers, A records, mail servers, SOA records for errors, consistency, accuracy and speed using several DNS tests. SolveDNS does not cache any test results, so you get a fresh report everytime you run the test for your domain names. If you would like to see more tests or have a question or a comment about a test result, please don't hesitate to use the email address in the footer.
intoDNS.com - intoDNS is a great tool for DNS Health Checking
    IntoDNS checks the health and configuration and provides DNS report and mail servers report. And provides suggestions to fix and improve them, with references to protocols’ official documentation.
openresolver.com - This will check to see if a DNS servers is recursive or not.
    This tool is for checking whether or not a DNS server is recursive or not.
digwebinterface.com - A great Web Interface for DIG with lot's of options
    This tool is not intended for automated lookups. Any other usage is in general welcome and free. To prevent abuse a CAPTCHA needs to be solved for every 100 lookups in a 24 hour period.
webdnstools.com - webdnstools.com
    Tools to check your entire domain DNS settings. Your mail or website not working? check here first!
kitterman.com - Kitterman SPF Record Checking tools
    Tools to check your DSN SPF records or Sender Policy Framework. SPF Testing
DNSChecker.org - A DNS propagation check of various points around the world.
    DNS Checker provides free dns lookup service for checking domain name server records against a randomly selected list of DNS servers in different corners of the world. Do a quick look up for any domain name and check DNS data collected from all location for confirming that website is completely propagated or not worldwide.
DNSStuff.com - DNS, Whois, Email Abuse Lookups, Email Blacklist Checking -
    This is a free web-based service for IT Professionals.
Zoneedit.com DNS Tools - Online DNS Check
    Zoneedit.com - A large DNS hosting company
centralops.net/ DNS Tools - Online DNS Check
    centralops.net/co/ - Another Excellent Checking tool.
https://www.zonemaster.fr DNS Tools - Online DNS Check
    www.zonemaster.fr/test/ - Checks your Entire Domain.
dnsperf.com DNS Performance Testing - Online DNS Performance Check
    DNS Performance Analytics and Comparison. More than 40 Million tests per day from all around the world.

Clustered Networks Inc.

Whether you have a network in your home or business, you need to make sure that it is secure and can be accessed remotely. It is essential that you have a complete look at your network from both internally and externally. We are all about Network Security!