The dig
command queries a nameserver and tells you all sorts of goodies. By default, it queries your local network's default nameserver. If you ask it for the NS
records of a domain, you get something like what I've included in the other file below.
Each record returned has a TTL, measured in seconds. When that number of seconds expires, the cache is flushed and the nameserver will go out to the internet to get fresh values.
So, look at one of the NS
records returned:
envatomarketplaces.com. 8839 IN NS ns7.markmonitor.com.
----------RR----------- -TTL--- -class- -type-- --------value-------