There are a number of NTP clients, most notably openntp but also some other ones, that increase their poll rate if they think there's something fishy with the time you're serving up. Maybe they think the "leap second pending flag" is something fishy and the increased polls correspond to when your server set the flag. Or maybe they thought the flag should've been set but didn't see your server setting it yet. Or maybe they were just overall confused by the "leap second pending" and decided to poll you more often for no other reason.
Now, the rational behavior of a NTP client is to poll a server less often if it doesn't believe that server... why ask if you won't believe the answer? But not all clients are rational. Tim. >>> Nelson Minar <[email protected]> 1/23/2009 12:54 PM >>> I just noticed an interesting traffic pattern on my pool server's logs: NTP traffic went up a huge amount right before the transition to January 1, 2009. You can see the change here: http://www.somebits.com/ntp/one%20month.html Requests / second went up from my usual 25 to nearly 300, a 12x increase. Some of the traffic may be new clients (I see a 3x spike in unique IPs), but a lot of it looks like existing clients sending more requests. Usually a single IP sends an average of 3 requests / 10 minutes, but during the spike interval it goes to 9 requests / 10 minutes, for a 3x increase. It's possible that's actually new clients sharing IP addresses of a NAT router. The oddest thing is the duration of the spike. I'd expect it to be a brief spike around 00:00 Jan 1 UTC as clients flubbed the leap second. But in fact the increase starts almost two days before and peaks several hours before 00:00. Any guesses what happened? Did other pool servers see the same spike? I have more data that could be analyzed if someone's really excited. PS: the pool server monitor thinks my offset was below 10ms most of the time over this time period. _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers _______________________________________________ timekeepers mailing list [email protected] https://fortytwo.ch/mailman/cgi-bin/listinfo/timekeepers
