I’ve been running an NTP server on this host for quite some time now. But as of yesterday, I’m a member of the pool.ntp.org group. pool.ntp.org is a round-robin-ish DNS service where requests for pool.ntp.org are given IPs from a huge block of listed nameservers, balancing the load across a pool of about 1,500 NTP servers across the world. The official “entry” for this server is my IP (220.127.116.11), but ntpd is actually listening on all IPs right now, so using blogs.n1zyy.com or ttwagner.com will work.
I’m currently synced to Stratum 2 servers, but I think that, after I finish up some open tasks (“real work,” versus playing with time servers), I’m going to look at requesting permission to sync to Stratum 1 servers. (Stratums, err, strata, are basically tiers. “Stratum 1” refers to a server directly connected to something like a GPS (which obtains extremely accurate time: having the correct time is an important part of how GPS works, so GPS actually broadcasts the time from the atomic clock) or from WWV (transmitted over HF radio). Stratum 2 servers get their time from Stratum 1 servers, and so on. As I sync to a network of stratum 2 clocks, I become a stratum 3 server. Moving up a stratum generally implies more accurate time, as there are fewer intermediaries to skew results. (Although we’re talking milliseconds of difference.) There aren’t an awful lot of stratum 2 servers, so syncing to a stratum 1 server would help to round out the stratum 2 list. (It would be fun to become a stratum 1 server, but as a stratum 2 host says of his data center, “they’re not going to let me drill a hole in the ceiling to run an antenna [for the GPS] to the roof.”)
For those of you with UNIX systems, take advantage of this! You can sync to me directly (18.104.22.168), or indirectly (the pool.ntp.org cluster). (Windows can sync to an NTP server as well, it’s just not a standard feature.)