Unable to connect to client PC

[superjennyradio]

I work for a small radio station and we recently had a power outage at our studios. The outage caused a host of problems, among them being IP Address issues within our automation network where we typically use static IPs. Once we re-established the proper IP addresses our VNC has been unable to connect to one of the PCs. (The most important one, of course) I have verified that port 5900 and 5800 are open. (It looks like our settings are set to "auto" for incoming connections, though) I can also ping that PC from the server PC from where we're trying to access it. Windows Firewall rules are set to allow both 5800/5900 from any local or remote address with TCP. I tried to connect by computer name (our typical way) and by IP address and neither work.

This machine is also sending data to a streaming PC for our online audio stream. I briefly switched the Incoming connections setting for specifically ports 5900 & 5800, then back to auto. We lost our online stream around the same time. It may have been coincidental as we've been having multiple issues due to the power outage. Long story, but at the time none of our stuff was actually protected by a battery back-up. We lost that a couple of weeks prior and were waiting for a replacement.

With all of that in mind, does anyone have any ideas? I'm not an expert in IT in any way, so I'm a little out of my depth at the moment.

Any help is appreciated.

[Bonji]

The only thing that jumps out to me is that you have static IPs and had to manage them lately. If you can, shut down the computer you are trying to connect to, and then try pinging that IP again to see if you still get a reply. If so, that would mean you have two devices using the same IP. Just enabling the firewall to block ICMP is not good enough because the switching/routing infrastructure may be directing traffic to one or the other device and you don't easily know.

If shutting down the computer is not an option, you can verify the VNC client computer is talking to the correct server. If both computers are on the same subnet, from the client you can run the command 'arp -a' in a command prompt (after successfully pinging the server) to list and verify the MAC address of the server computer to ensure you're talking to what you think you are talking to.

If you determine traffic routing isn't the problem, then it would seem to be a problem with the VNC server computer.

[Apollo]

I have the same problem. I can ping the computer I am trying to connect to (server) from my computer (client). arp -a shows that the IP address is mapped to the correct MAC address. I try to connect with actual IP address and still it will not connect. I have no other firewall than windows defender. What else on the server computer could be stopping this from working?