If you don't need ipv6 and wanna keep network "clean" especially for local servers/services you can easily disable ipv6. 1. check to see ipv6 under interfaces configuration (you can see ipv6 info for every interface) ip a sh 1: lo: mtu 65536 qdisc noqueue state

With systems that are using systemd[1] as init system there is no need to install ntpd daemon anymore if you only need to sync local time with your NTP server. On Debian distro systemd-timesyncd service can be found by default from Stretch (9.0) version. So in order to