Hi Wilfred, Atleast your probes were online for many number of days. Here is the availability report of my V1 probe 0303. 99.71% Availability. +---------------------+---------------------+------------+--------------+ | Connected (UTC) | Disconnected (UTC) | Connected | Disconnected | |---------------------+---------------------+------------+--------------+ | 2014-05-29 23:46:12 | 2014-06-02 06:30:06 | 1d 06:30 | 0d 00:00 | | 2014-06-02 06:40:35 | 2014-06-03 06:52:14 | 1d 00:11 | 0d 00:10 | | 2014-06-03 06:59:53 | 2014-06-04 22:11:56 | 1d 15:12 | 0d 00:07 | | 2014-06-04 22:22:43 | 2014-06-16 15:48:25 | 11d 17:25 | 0d 00:10 | | 2014-06-16 15:59:17 | 2014-06-17 22:11:24 | 1d 06:12 | 0d 00:10 | | 2014-06-17 22:22:53 | 2014-06-21 21:13:51 | 3d 22:50 | 0d 00:11 | | 2014-06-21 21:41:35 | 2014-06-23 15:44:56 | 1d 18:03 | 0d 00:27 | | 2014-06-23 15:54:55 | 2014-06-29 04:19:02 | 5d 12:24 | 0d 00:09 | | 2014-06-29 04:53:22 | Still up | 1d 19:06 | 0d 00:34 | +---------------------+---------------------+------------+--------------+ It is directly connected to our core router. I was never able to correlate any of the disconnection times with any network incident. Best Wishes, Aftab A. Siddiqui -----Original Message----- From: ripe-atlas-bounces@ripe.net [mailto:ripe-atlas-bounces@ripe.net] On Behalf Of Wilfried Woeber Sent: Thursday, July 17, 2014 5:49 PM To: ripe-atlas@ripe.net Subject: [atlas] some thoughts and question regrding probe "stability" Hi Folks, triggered by the discussion related to DNSMON, and an issue (power, resolved) with one of my V1 probes, I'd like to get some input or start a disussion or an investigation. To start with, I am not very clear what the term "stability" w/should mean in this context, as the probes are supposed to buffer measurment data locally, at least for a while (true?). So, here goes... Obviously, looking at some Atlas Stat pages, there are probes with a 100% uptime. Now, looking a the 3 under my supervision (2x V1, 1 Anchor), ref "Connected" and "Disconnected", there's no chance to get near that value, as all of them tend to topple over on a regular basis, mostly for a *short* period of time in the range of 0m(!) to some 30+m. With respct to the bahaviour of the Anchor, which is mounted in the same rack as the backbone router it connects to, in a Data Center, we tried to correlate the (reported) disconnection events with the router and interface logs for the probe. No luck there, also, no maint works or the like, so I presume the Anchor didn't reboot or that there were "real" network problems. Let's compare the most recent dis/connection logs for my 3 pets: ID 6009 2014-07-14 03:58:03 3d 8h 16m Still Connected 2014-05-27 03:03:54 48d 0h 46m 2014-07-14 03:50:47 0h 7m 2014-05-20 15:19:02 6d 11h 37m 2014-05-27 02:57:00 0h 6m 2014-05-14 21:16:56 5d 17h 59m 2014-05-20 15:16:22 0h 2m 2014-04-08 16:03:21 36d 5h 1m 2014-05-14 21:05:17 0h 11m ID 0466 2014-07-13 23:31:05 3d 12h 45m Still Connected 2014-07-09 23:05:40 3d 23h 54m 2014-07-13 22:59:49 0h 31m 2014-06-16 10:53:21 23d 11h 55m 2014-07-09 22:49:04 0h 16m 2014-05-25 09:03:06 22d 1h 38m 2014-06-16 10:42:00 0h 11m 2014-05-24 20:34:50 11h 54m 2014-05-25 08:29:12 0h 33m ID 0414 2014-07-07 23:41:23 9d 12h 35m Still Connected 2014-07-02 03:58:45 5d 19h 31m 2014-07-07 23:29:54 0h 11m 2014-06-13 09:37:50 18d 18h 7m 2014-07-02 03:45:08 0h 13m 2014-06-08 13:22:14 4d 20h 7m 2014-06-13 09:29:38 0h 8m 2014-05-21 08:29:23 18d 4h 45m 2014-06-08 13:15:11 0h 7m Again, I fail to see some obvious correlation, what am I missing? Does anyone else see a similar pattern? How to start debugging, if there's anythig that needs debugging? Thanks for your ideas and help! Wilfried