I have a new Mac Mini, and an older MacBook. Both are running up-to-date Tahoe. Both are on the same local network, which otherwise has been working fine for years. Both are wired through a switch to the same LAN port on the router, and both have WiFi shut off; there’s only one real interface configured on each machine.
The LAN is supported by a router that has DHCP and a DNS server. For several of the clients in my network, I have the router configured to give out static IP addresses. The router also hands out a fake domain name, basically “myname.home”. Thus usually from one machine, say my old MacBook “oldmac”, I can type:
ssh newmac
and that works: the oldmac first tries the default domain it got from the router, “myname.home”, and asks my DNS server for “newmac.myname.home”. The router correctly responds with the internal address for “newmac” and everything is fine.
However, for reasons unknown, the “newmac” machine does not work. After some investigation and after installing Wireshark, here’s what I notice:
- From “oldmac”, I can fire up Wireshark with a display filter of “dns and ip.dst==192.168.50.1” (the router), and then in a terminal do some command like
host google.comand I instantly see the DNS packets in the Wireshark UI. As expected. - From “newmac”, I never see DNS packets in Wireshark. I fire it up the same way, with that same display filter, and I get nothing, no matter what sort of lookups I trigger. Even using
digI see no DNS packets at all.
As far as I can tell, all the networking options in MacOS are the same between the machines, other than their host names. Clearly they’re not the same, but I don’t know how. What I also don’t understand is what the new machine is doing to get any IP addresses if it’s not sending DNS packets somewhere. (It does work otherwise however; I can use the new machine mostly normally.)
What’s going on?
There’s an earlier version of this question that includes some more info, but this question here I think is the root of the problem. It doesn’t matter how my DNS server is set up if the new Mini won’t even talk to it.
