APM - WEBSSO - Log url when websso error generated

Hi,

 

How it's possible to log url of request when an error of WebSSO it's generated ?

 

In iRule, I don't find if specific event exist to do something in this event like log information.

 

In production, we have some log like this and I don't find the context of this error : 014d0005:3: Kerberos: can't get S4U2Proxy ticket for server HTTP/external-url@DomaineAD - KDC can't fulfill requested option (-1765328371)

 

It's normal, I get this error because SPN for external url doesn't exist but in LTM Policy rewrite host with internal Host, so APM doesn't see external url normally.

 

WebSSO SPN Pattern used : HTTP/%h@DomaineAD

 

Best regards