Hi! I noticed that Phillip Homburg merged a RIPE Atlas client patch in November of last year, based on our request, that removes the Atlas probe's inability to test addresses in 0/8 and 240/4. https://github.com/RIPE-NCC/ripe-atlas-probe-measurements/commit/59475f848b2... So, I just tried a couple of measurements to 240.1.2.3 to see how Atlas would handle them: https://atlas.ripe.net/measurements/48100582/ https://atlas.ripe.net/measurements/48100585/ (I don't expect these to succeed, as no part of 240/4 is publicly announced in BGP; the interesting information to be garnered from this isn't whether the probes succeed, but how they fail.) For the first measurement, with ping, 6 hardware probes and 4 software probes all gave the same result: "Unreachable" (which is what you would get if you ran this on any ordinary Internet host with command-line ping). For the second measurement, with traceroute, 6 hardware probes all actually attempted the traceroute (getting failures after some small number of network hops), while 3 software probes all reported back "!address not allowed". What could account for the difference in how hardware and software probes handle this task? I would have thought that the change from last November would make software probes willing to attempt these.