NTLM SMB issue - Could not get valid NTLM challenge from ........

I'm trying to debug an issue with NTLM failback, I have the filter configured correctly as per any other deployments.

I'm able to authenticate users correctly using Kerberos, but I have noticed in the logs an issue with NTLM.

This was discovered because of a Java Applet which is posting back to the server, the applet is not using kerberos but NTLM to authenticate the user.

The application server is Tomcat 5, using Quest VSJ "VSJ Standard Edition 3_3 Patch 3548"

From what can be seen within the server logs is that QuestSSO performs a DNS lookup and attempts to connect to all of the GCs which are returned.

Example:
- Starting Coyote HTTP/1.1 on http-80
- JK: ajp13 listening on /0.0.0.0:8009
- Jk running ID=0 time=0/47  config=null
- Host server1.domain.ltd/1.1.1.1:389 appears to be down
- Could not get valid NTLM challenge from server1.domain.ltd/1.1.1.1
Exception: com.wedgetail.idm.sso.ntlm.NtlmException: NTLM challenge was null
- Host server2.domain.ltd/1.1.1.2:389 appears to be down
- Could not get valid NTLM challenge from server2.domain.ltd/1.1.1.2
Exception: com.wedgetail.idm.sso.ntlm.NtlmException: NTLM challenge was null
- Host server3.domain.ltd/1.1.1.3:389 appears to be down
...
... etc


I have enabled the debug level and log4j configuration, but this is not showing any errors.

I have used PortQry.exe to scan the AD servers and they are accessible.


What can I do to move forward? Any ideas ?