On 15 Nov 2023, at 10:27, Jonathan Ryshpan <jonrysh@pacbell.net> wrote:

I suspect that the dns server for my local net did not recognize the upgraded machine for a while, but then started to when something timed out. Ssh is working, and also the machine (a server) is now visible.

I sometimes have to flush the DNS cache on machines to fix this type of issue.

macOS is particularly bad for this, but Windows and Fedora get stale as well.

You can use the dig command to get DNS info directly from your DNS servers to

find out what your DNS servers know about and compare to the output of host command.

Barry