Using a Raspberry PI as a Router and Wifi hotspot with a firewall for your internal LAN or household network is now possible. The Wifi hotspot can function as a hotspot for guests. This can be more secure then the cheap nasty routers supplied by your ISP with hard coded passwords.
Using chrony on Ubuntu 18.04 will show how to setup chrony for clients and servers within your LAN. Chrony replaces NTP which in now depreciated. Using chrony on Ubuntu 18.04 will show how to setup chrony for clients and servers within your LAN.
Chrony is an implementation of the Network Time Protocol (NTP). It is used to keep the system clocks of PCs synchronized with the clock of NTP servers. It can also be used to setup your own NTP server to provide time for your LAN. Chrony replaces ntp and ntpdate which are now deprecated.
Setting up NTP on Ubuntu 16.04 is a really quick post, as most Linux (or M$ Windows) installations will use/need an NTP server to keep the time in sync with other machines on the LAN. Services such as DNS, DHC, LDAP, email, Mythtv, syncing data between machines to name just a few.