I'm not sure this is a Q for this forum, but I start to run out of ideas, and I'm a bit annoyed by the problem. It's about macOS or maybe some addon's software. I think it's a strange problem, and it might be core component related.
I try to reach arduino.cc, but I can't do a DNS lookup. Using Wireshark, I can see the request going out over the WiFi. At least wherever Wireshark 'catch' its packets. Looking in the router (packet capture on the incoming interface, OPNsense), I never see the DNS request for arduino.cc. This is also true for news.cc. I have no problem with other DNS lookups, like apple.com or learn.edu. I have not found any other top domains with the same problem. I have done the "sudo dscacheutil -flushcache ; sudo killall -HUP mDNSResponder" and turned off/on WiFi. Restart does not help. "dscacheutil -q host -a name arduino.cc" don't show anything in cache, and it fails to look up the name with the same result. Wireshark sees arduino.cc request, but nothing appears on the router's incoming interface. I don't use Cisco AnyConnect, but I use Apple's own Cisco VPN IPsec. It does not make any difference with or without the VPN connected or disconnected. Still cant ask for .cc domains? This has been going on at least for a year or two.
Any advice on how to troubleshoot this further, please?
Have Little snitch installed, but it did not help to turn the network filter off. I have AirTool2, but no change if I shut it down either. I use macOS 12.3.1. I have both OpenVPN and Fortinet's FortiClient installed, but neither is running/open.
Best Regards.
- Per Håkansson