Hi, My two RIPE Atlas probes have been acting strangely over the past several months. Very frequently I receive automatic notices from the RIPE Atlas system that both of my probes have been "disconnected from the RIPE Atlas infrastructure" essentially simultaneously. Here's the history from 2018: probe 11171 2018-02-23 18:08:57 UTC. probe 11203 2018-02-23 18:10:23 UTC. probe 11171 2018-06-21 04:32:15 UTC. probe 11203 2018-06-21 04:30:59 UTC. probe 11171 2018-06-24 05:36:57 UTC. probe 11203 2018-06-24 05:37:04 UTC. probe 11171 2018-07-31 20:25:27 UTC. probe 11203 2018-07-31 20:25:32 UTC. probe 11171 2018-08-18 04:48:20 UTC. probe 11171 2018-09-15 02:31:26 UTC. probe 11203 2018-09-15 02:31:28 UTC. probe 11171 2018-10-15 23:03:50 UTC. probe 11203 2018-10-15 23:04:06 UTC. probe 11171 2018-11-16 14:42:28 UTC. probe 11203 2018-11-16 14:42:33 UTC. (Those last three events are eerily periodic.) Each time when I am finally able to visit inspect the probes (both are reported as "Firmware Version 4940 (1100)"), their LEDs are in the same state: --------------- Looking at the units with the on/off LED to the left: (1) the left-most (on/off) LEDs are on steadily. (2) the next LED is off. the next two LEDs are flashing at different frequencies: (3) the next flashes on approx. 48 times per minute (4) the next flashes on approx. 110 times per minute (5) the centers of the wide "WPS/RESET" LEDs are on steadily. --------------- Once these probes fail they remain offline until I try turning it off and on again. The probes are powered similarly: the RIPE-provided USB cable is plugged into an Apple iPhone USB power adapter, in turn plugged into a standard US 120v / 60 Hz AC receptacle. However, the AC power circuits feeding these receptacles come from two very different sources which should not share fate. Until today both probes have been plugged into ports on the same Cisco switch, but after today's disconnect I moved probe 11203 to a different physical switch that has the same VLANs. None of my other equipment experiences any troubles around the times when these events happen to my RIPE Atlas probes. In the past I have reported these events to atlas@ripe.net, but I doubt that the causes cited (e.g. "the problem is with your dns") have been accurate. (I do not blame the atlas@ripe.net folks who have responded. Something strange is happening here, and I haven't yet cracked it.) I'm curious whether anyone else sees similar behaviors, or has suggestions for ways to determine what is happening. Thanks! Jay B.