Small business, retiring our old WSUS server which was ws2003. I made a new 2012 R2 server and named it the same as the old server, for reasons unrelated to WSUS (LOB app that makes it easier this way). Of course the old server was renamed and given a new IP first. The new server has the same IP as the old server had, so DNS is unchanged.
I installed the WSUS role and related features (IIS etc). Because the old server was pretty crudded up and the cleanup wizard could never complete even after running for days, I decided to not migrate but just start over, fresh. I configured the new one from scratch (products, auto-approvals etc) and completed a first sync with MS as the upstream. It's configured the same as the old server.
The GPO that points clients to WSUS still has the same URLs for WUServer and WUStatusServer, but no clients are showing up. How do I get clients to check in with the new server? Clients must be using more than just a URL, like is there a GUID or certificate or such? We are just using http for now so I don't think it's SSL. Windows firewall on the WSUS server has the right entries I think.
Grateful for any advice