The host names of the computers in this network were managed through the use of a single HOSTS file located on a centrally administered server.
As each DNS record comes with a Time To Live value which will oblige each DNS server in the resolution chain to do caching during the amount of seconds mentioned by this value.
So not only you can cache in your machine, but CERTAINLY the result of the name lookup will be cached somewhere on a server you don't control.
The original DNS was based on Request for Comment (RFC) 882 (“Domain Names: Concepts and Facilities”) and RFC 883 (Domain Names–Implementation and Specification), which were superseded by RFC 1034 (“Domain Names–Concepts and Facilities”), and RFC 1035 (“Domain Names–Implementation and Specification”).
Additional RFCs that describe DNS security, implementation, and administrative issues later augmented the original design specifications.
As the number of hosts on the Internet grew, the traffic generated by the update process increased, as well as the size of the HOSTS file.
The need for a new system, which would offer features such as scalability, decentralized administration, support for various data types, became more and more obvious.If you are running with stock settings it won't be caching dns, as for it to do so you have to explicitly set it up as this Ubuntu article describes.If you wanted to refresh your settings you could disable and then enable networking or run will be taking the settings direct from your router and your connection will be automatically established when you login to Ubuntu./usr/sbin/dnsmasq \ --no-resolv \ --keep-in-foreground \ --no-hosts \ --bind-interfaces \ --pid-file=/var/run/Network Manager/\ --listen-address=127.0.1.1 \ --conf-file=/var/run/Network Manager/\ --cache-size=0 \ --proxy-dnssec \ --enable-dbus=org.freedesktop.Network Manager.dnsmasq \ --conf-dir=/etc/Network Manager/dnsmasq.d cache DNS, it isn't caching out the box.The only solution to be immediately notified of a name record change is to use a TTL value of 0 when creating / updating the entry in the authoritative name server.