Embodiments are directed to monitoring network traffic using network monitoring computers (NMCs). Networks may be configured to protect servers using centralized security protocols. Centralized security protocols may depend on centralized control provided by authentication control servers. If a client intends to access protected servers it may communicate with the authentication control server to obtain keys that enable it to access the requested servers. NMCs may monitor network traffic the centralized security protocol to collect metrics associated with the control servers, clients, or resource servers.