Kerberos will only be negotiated when it is possible in the first place. Even if you have it configured and it has worked at any given moment the browser may have to fall back to NTLM
If you need to identify what is being used at this moment the only way to recognize this is from the logs at log level 4.
Once Kerberos authentication is enabled in EasySSO settings - the server and the browser will start exchanging "Negotiate" headers.
If NTLM is still being used the value of the headers being sent by the client will start with "TlRMTV" and authorization will take 3 request/response roundtrips:
tail -f jespa.log | grep -e "C:" -e Authorization -e Authenticate -e Exception -e authenticated
...may result in something similar to:
2015-11-08 15:57:29: HttpSecurityService: C: GET /jira/ 2015-11-08 15:57:29: HttpSecurityService: WWW-Authenticate: Negotiate 2015-11-08 15:57:29: HttpSecurityService: C: GET /jira/ 2015-11-08 15:57:29: HttpSecurityService: Authorization: Negotiate TlRMTVNTUAABAAAAl5JI4gAAAAAAAAAAAAAAAAAAAAAGAbEdAAAADw== 2015-11-08 15:57:29: HttpSecurityService: WWW-Authenticate: Negotiate TlRMTVNTUAACAAAAEAAQADgAAACVgoliFU7pvXnv8yDFAAAAAAAAAFgAWABIAAAABQLODgAAAA9UAEUAQwBIAFQASQBNAEUAAgAQAFQARQBDAEgAVABJAE0ARQABAAwAagBlAHMAcABhADEABAAYAHQAZQBjAGgAdABpAG0AZQAuAG8AcgBnAAMAEABLAHkAbwBuAC4AbABhAG4AAAAAAA== 2015-11-08 15:57:29: HttpSecurityService: C: GET /jira/ 2015-11-08 15:57:29: HttpSecurityService: Authorization: Negotiate TlRMTVNTUAADAAAAGAAYAJgAAAD4APgAsAAAABAAEABYAAAAEgASAGgAAAAeAB4DDFAELAAFYKIYgYBsR0AAAAPtcH9EMsNOMFTt0vhJXwAZVQARQBDAEgAVABJAE0ARQB0AGUAcwB0AHUAcwBlAHIAMQBXAEkATgAtAEQARABFADAATwA0ADIASQBUAEsAMQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAnlo2EpEYci9RBB47bLJXrAQEAAAAAAAC86Aw10RnRAXb9POTsFtKhAAAAAAIAEABUAEUAQwBIAFQASQBNAEUAAQAMAGoAZQBzAHAAYQAxAAQAGAB0AGUAYwBoAHQAaQBtAGUALgBvAHIAZwADABAASwB5AG8AbgAuAGwAYQBuAAgAMAAwAAAAAAAAAAEAAAAAIAAAcRkMdbuNloshgez1/yX1nNTlxK+ZtsZGwScVNIFXwGgKABAAAAAAAAAAAAAAAAAAAAAAAAkAJABIAFQAVABQAC8AMQA5ADIALgAxADYAOAAuADEAMwAzAC4AMQAAAAAAAAAAALmhXivglKIpv+DHkwe6PmE= 2015-11-08 15:57:29: NETLOGON: Session authenticated 2015-11-08 15:57:29: HttpSecurityService: 192.168.133.135:57548: testuser1 successfully authenticated
If Kerberos is being used the headers will not start with "TlRMTV" and authorization will take only 2 request/response roundtrips:
2015-11-08 13:36:35: HttpSecurityService: C: GET /stash/ 2015-11-08 13:36:35: HttpSecurityService: WWW-Authenticate: Negotiate 2015-11-08 13:36:35: HttpSecurityService: C: GET /stash/ 2015-11-08 13:36:35: HttpSecurityService: Authorization: Negotiate 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 2015-11-08 13:36:35: HttpSecurityService: 192.168.133.136:63668: testuser1 successfully authenticated