I have a server that is host a MSSQL database and some other server related tasks.
The server communicaties with a large number of devices. The devices send data to the server.
The communication links are down between the devices on the intranet and to the outside world. However it seems I can ping and can be pinged from machines on the same switch.
This includes the DNS Servers.
When I run,
C:\ipconfig /registerdns
I get
RPC Server is Unavailable.
So, it seems that the server can not verify the DNS server. Both DNS server are up and running. No other machines are affected on the network.
Nothing was wrong with the server.
The networking crew blocked the server due to updates that were not preformed to fix Adobe vulnerabilities.
There was a lack of communication to (1) get the updates installed and (2) that the server was blocked.
So, I guess the lesson is communicate.
Sorry for the goose chase and thanks.
Check on the SQL Server that the DHCP Client Service is running as that is responsible for dynamic updates. See MS KB264539 - Dynamic DNS updates do not work if the DHCP client service stops.