chris <chris-nos...@tridac.net> wrote: > On 06/25/21 17:28, Jim Pennino wrote:
<snip old stuff> >> Or for $14/machine I could use a USB GPS, my machine with PPS GPS, and A >> public server that does NOT request use of DNS which yields 3 sources of >> time without using a pool or DNS lookups. >> >> Or for $28/machine I could use 2 USB GPS receivers and my machine with >> PPS GPS, which also provides 3 sources of time without any network >> access at all. >> >> > > Your choice, but when I registered the ntp server here with the pool, I > just used the fixed ip address. That's what they ask for and it does > bypass dns altogether. The less translation the better, unless > you really need it... Actually what I plan to do is to put a $14 USB GPS on the machine that already has a PPS GPS attached and do away with ALL external machines. If there are two GPS receivers attached to the machine I have a backup if one receiver fails. As GPS receivers are highly unlikely to fail in some wonky mode, e.g. time being off by some large amount, but to fail completely, there is no need for any other reference source while I replace the failed receiver. Now if there is a Carrington-class coronal mass ejection or WWIII breaks out, I will lose all time references but I will have lots of other things to worry about that are much more important than the computer clock and it is likely that all internet access will also be down. Then on two other machines I attach two $14 USB GPS receivers and no external references. These three machines then provide time for all other machines on my network. The three machines will provide the redundancy needed for when one of those machines gets rebooted for updates/upgrades. Done. The only foreseeable change to that I might ever make is if and when USB 3.0 GPS receivers with PPS become cheap and available, I might swap out the USB receivers with one of those just to see how well they work. Yes, this scheme only gets my machines to within 10s of milliseconds to the actual time, but that is good enough for me. If I needed better, I would buy one of the $685 GPS GNSS Disciplined Rubidium clocks off ebay and get time to the nanosecond. _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
