With IPHost Network Monitor you can run WMI Forms Authentication Failure monitoring of various devices in your network.
To create a WMI monitor for Forms Authentication Failure, provide host name (it must be a Windows host) and specify custom WQL query:
Number of failed forms authentication ticket validations since the application was started.
ASP.NET application performance counters
IPHost Network Monitor is an advanced and easy tool for monitoring LAN and WAN networks, network servers, workstations and TCP/IP devices. Use IPHost Network Monitor to monitor your servers, domains, computers and devices.
