I found variations to my question but I'm not sure those other topics answer my question specifically.
I have several smart switches on which I have flashed custom firmware. One of the primary reasons for having taken this step is so the devices operate without having to contact a cloud service external to my home network. The operation of the switches is no fully dependent on a live connection to the Internet.
I just realized that I did not address one issue that still requires that they reach the Internet - syncing their time with an NTP server. I would like to set up a time server on my LAN that I can point my IoT devices to to obtain their time sync.
I can configure the devices to any NTP server URL I wish. Currently each device has three NTP entries. I'd like to change the primary entry to point to a Raspberry Pi that can service the devices' time sync requests. I know it's possible to set my Raspberry Pi as an NTP server.
Release = Raspbian GNU/Linux 9 (stretch) Kernel = Linux 4.14.79-v7+ Platform = Raspberry Pi 3 Model B Rev 1.2
My question is this... Can the Raspberry Pi be set up to set it's clock by making Internet NTP requests (i.e., its an NTP client behaving as usual), and then it acts as an NTP server to my LAN devices using the time it obtains from the Internet?
Are there any issues with synchronization of timestamps the devices received from the Raspberry Pi vs. the timestamps that they receive from the DHCP server when the device requests its IP address? Is there going to be a conflict with my router?
I may not even be thinking of all the ramifications. Regardless, net-net, can the RPi serve up its clock time which it obtains from an Internet NTP server to my LAN devices? I want to avoid adding an RTC or GPS device as a prerequisite to just pointing my smart switches to a local time server.
Thank you in advance.