Quite often I am wondering if a site is using Kerberos or NTLM. You can use tools like Fiddler, Network Monitor and such for that. But sometimes I just want to have a simple tool without installation like when working on computers where you can't install such software but are allowed to run executables. For that I have created a tool: Kerberos Authentication Tester.

Kerberos Authentication Tester Features:

• It shows what authentication method is used in a web request: None, Basic, NTLM or Kerberos
• It shows the SPN used in case of Kerberos
• It shows the HTTP status
• It shows the HTTP Headers of the request.
• It shows the version of NTLM used (v1 or v2)
• It has a detailed view with a complete breakdown of the Authorization header. (Yep, went through all the RFCs to dissect the Kerberos and NTLM packages)
• It shows your current Kerberos tickets and allows you to remove them (like klist.exe)

Some Screen shots:

The main form:

The blue details link at the top right shows a new screen with the details of the request, including a breakdown of the Authorization HTTP Header. You can also save this XML.

Use different credentials or a proxy:

And it also has quick access to the Kerberos Ticket of the current users. And you can even delete them.

It's still in beta, so your mileage may vary ;-)