TGS-REQ and PA-TGS-REQ

[Joey Collins]

Hi, I have a forwardable ticket-granting-ticket from a client system C1
on my server (S1).  I'm attempting to jinn up a TGS-REQ message on S1
(which will be sent to the KDC) to request a service ticket to a 3rd
machine (S2) from the KDC on behalf of the client using the forwardable
tgt. i.e.:

C1 -> S1 -> S2
       |
       |
       V
      KDC

The padata[3] field is confusing me--do I need to first request a
service ticket from the KDC for S1 <--> KDC then put it in padata?  Or,
do I put the forwardable ticket-granting-ticket in padata[3]?
additional-tickets[11] seems like the right place for the forwardable
tgt, is this correct?

thanks for the help.
Joey.