[Samba] necessary to join pdc to domain?

[Leandro Tracchia]

is it necessary for me to join the PDC itself to the domain??

i ask this because the below command is not working for me:

root# net rpc testjoin
[2008/05/20 11:24:32, 0]
rpc_client/cli_pipe.c:get_schannel_session_key_common(2445)
  get_schannel_session_key: could not fetch trust account password for
domain 'LSA'
[2008/05/20 11:24:32, 0] utils/net_rpc_join.c:net_rpc_join_ok(70)
  net_rpc_join_ok: failed to get schannel session key from server
GISKARD for domain LSA. Error was NT_STATUS_CANT_ACCESS_DOMAIN_INFO
Join to domain 'LSA' is not valid

good news is i can join the domain from windows clients without a problem