We are using SP2010 on-premise. On last weekend the server (both SharePoint and SQL are installed in same machine) was patched for some security hotfix and .net framework.
On Monday, we found we no longer able to login CA using Farm administrator account. We have tried login localhost or from a remote client PC (which can login before), it will show a password prompt 3 times.
We can successfully login with same login/password for all the other SharePoint sites on same farm. The right top corner will show the login is "System account". Hence the login/password have no problem.
It looks like everything is working beside we cannot open CA. What could be the problem? Is login to CA have different authentication protocol as other site collections?