mhost

The primary objective of mhost is to lookup DNS queries similar to the Unix host command line tool. In contrast to host, mhost queries multiple server parallel and compares their results. In this way, you can check, if queried DNS servers return the same results.

There are different situation in which DNS servers might return deviating results. The most simple case it caches which have not yet been updated. After a zone updates, it takes time until DNS servers around the world pick up the changes. Another case is misconfiguration of zone's primary DNS server and failed AXFR zone transfers. Last, but not least, a internet service provider or any other authority might want to silently divert your request to another target.

In all these cases, mhost can help you to figure out what's going on.

Use Cases

Use Operating System's default Resolver and Google's public DNS servers

mhost -s 8.8.8.8 -s 8.8.4.4 github.com

Use 100 DNS German Servers from ungeflitert-surfen

mhost -u de github.com

Output JSON for Post-Processing

mhost -u de -o json github.com

Thanks

Thanks to Benjamin Fry for his literally wonderful TRust-DNS server and the corresponding client library which does all the heaving lifting of host.