one machine on the domain has had the same static internal ip a long time, serving a couple small sites. All of a sudden internet connectivity is not available, although the LAN is. Switching to dhcp gets a new dynamic address which then works. Assigning that new ip as static continues to work, but trying to use the old static ip fails.
What should I look for as a cause? Windows updates have occurred, but nothing else that I see is changed at all in the firewall or in any configuration I have done.
You got some chaos in your setup. You're using static ip in DHCP subnet which can cause conflicts since dhcp may assign same ip address that you are having as static.
Can you try
pinging
the old static IP? maybe some device is using it and you get ip conflict although it should be 'announced' by system. Also can you run Colasoft MAC Scanner (free version) and see if you have any device taking your ip?Also make sure you can ping/access dns when having static ip.
When you have the original static IP assigned to your server I would try:
I'm guessing your tracert will fail, which means your router is blocking access to / from the internet.