Title: Port of the week: dnstop
       Author: Solène
       Date: 18 April 2018
       Tags: unix
       Description: 
       
       Dnstop is an interactive console application to watch in realtime the
       DNS queries going through a network interface. It currently only
       supports UDP DNS requests, the man page says that TCP isn't supported.
       
       It has a lot of parameters and keybinding for the interactive use
       
       To install it on OpenBSD: `doas pkg_add dnstop`
       
       We will start dnstop on the wifi interface using a depth of 4 for the
       domain names: as root type `dnstop -l 4 iwm0` and then press '3' to
       display up to 3 sublevel, the `-l 4` parameter means we want to know
       domains with a depth of 4, it means that if a request for the domain
       my.very.little.fqdn.com. happens, it will be truncated as
       very.little.fqdn.com. If you press '2' in the interactive display, the
       earlier name will be counted in the line fqdn.com'.
       
       Example of output:
       
           Queries: 0 new, 6 total                           Tue Apr 17
       07:17:25 2018
       
           --------------- --------- ------ ------
           perso.pw                3   50.0   50.0
           foo.bar                 1   16.7   66.7
           hello.mydns.com         1   16.7   83.3
           mydns.com.lan           1   16.7  100.0
       
       If you want to use it, read the man page first, it has a lot of
       parameters and can filters using specific expressions.