no PTR is needed for TGS-Req in openjdk7?

[Roy Golan]

I all,

In our project (www.ovirt.org) we do some kerberos authentication and 
we've seen different behavior between jdk6 and 7 in the process
of doing the TGS-Req to the KDC. with jdk6, wh must have a PTR record 
for our KDC to run while using jdk7 we see its ignoring it.
To check it we have put a wrong record in /etc/hosts for our KDC server, 
say "1.1.1.1 wrongkdc.example.com" while it should be kdc.example.com and
we saw that jdk6 is failing with PRINCIPAL_UKNOWN . the PRINCIPAL in 
jdk6 is 1.1.1.1/wrongkdc.example.com and with
jdk7 is 1.1.1.1/kdc.example.com which is why it works.

is this a change is by design or maybe a bug? can someone explain if 
there is no intent
of using reverse records (PTR) for the PRINCIPAL in TGS requests?

I can supply tcp dumps if that will help to shed light here.

Thanks,
Roy