Error 1219 on server

I saw error 1219 and message like "Multiple connections to a server or shared resource by the same user, using more than one user name, are not allowed. Disconnect all previous connections to the server or shared resource and try again." on one of application servers with strange access to resources. To avoid restart of the whole server I restarted workstation service.
But (update) it wasn't enough - so - I created entries in the hosts file - and currently it is working perfectly.

DNS performance on Windows

Just to remember: I've got experience with heavy loaded domain controller with queries rate above 40k per second (yes, 40 thousand per second). The main problem on this virtual domain controller it was high cpu0 utilization and low load on other cpu. As I can remember - it was VMWare vm with 16 cores (virtual cores on operating system). What should be done in this case to improve performance? Upgrade of virtual hardware and network subsystem.