mDNSResponder is clearly broken on the latest version of Ventura (13.2.1) - how could this go unnoticed?
I got a brand new MacMini a few weeks ago which had Ventura on it. It was working perfectly.
However, after I upgraded to the latest version of Ventura DNS resolution broke. If I try to "ping" a domain, the ping program hangs as of course does Safari and any other regular application that wants to connect to a server. Pinging an IP address works fine.
Both NSLookup and Dig (neither of which use mDNSResponder) were also working fine.
In other words, this is not an internet connectivity issue, it is explicitly a DNS resolution issue (and nothing to do with invalid DNS server addresses :-) )
I called Apple Support and tried explaining this to their support people, including a "senior" advisor, but they all got hung up on wanting to know what happened when I open Safari and I could not get them to understand that the problem had nothing to do with Safari.....very frustrating.
However, I discovered that after my machine finishes booting up, if I "kill -9" the mDNSResponder and its helper processes, they of course immediately restart and DNS starts working properly.
This is 100% reproducible --- shutdown the machine, reboot it, DNS is broken --- kill -9 the mDNSResponder and helper, they restart and DNS works perfectly. I did this four times while on the phone with Apple Support.
Obviously I have no access to the code but I bet that the problem is that mDNSResponder is starting before there's an available IP address and just hanging. That would explain (a) why it doesn't work immediately and (b) why it starts working as soon as you restart the mDNSResponder processes.
Very frustrating.
Mac mini (M2, 2023)