Binary package “djbdns” in ubuntu xenial

a collection of Domain Name System tools

 This package includes software for all the fundamental DNS operations:
 .
 DNS cache: finding addresses of Internet hosts. When a browser wants to
 contact www.hotwired.com, it first asks a DNS cache, such as djbdns's
 dnscache, to find the IP address of www.hotwired.com. Internet service
 providers run dnscache to find IP addresses requested by their customers.
 If you're running a home computer or a workstation, you can run your own
 dnscache to speed up your web browsing.
 .
 DNS server: publishing addresses of Internet hosts. The IP address of
 www.hotwired.com is published by HotWired's DNS servers. djbdns includes
 a general-purpose DNS server, tinydns; network administrators run tinydns
 to publish the IP addresses of their computers. djbdns also includes
 special-purpose servers for publishing DNS walls and RBLs.
 .
 DNS client: talking to a DNS cache. djbdns includes a DNS client C
 library and several command-line DNS client utilities. Programmers use
 these tools to send requests to DNS caches.
 .
 djbdns also includes several DNS debugging tools, notably dnstrace, which
 administrators use to diagnose misconfigured remote servers.
 .
 See http://cr.yp.to/djbdns.html