As noted in the original post, all internet operations work, i.e., I can point a web browser to any website on the net and access systems I have set up on my LAN via samba. I point the DNS lookup to my router. I don't use web proxies, or proxies of any kind.

Yep, thinking about installing wireshark, but was hoping that someone here knows the IP address that it is looking for, or if it is using a URL, what it is.