NT5 joining domain

[Luke Kenneth Casson Leighton]

ok.  examination of network traffic shows that when a GETDC or SAMLOGON
request is received, an NT4 PDC checks to see if the target host is up and
running (by doing a Node Status Request) BEFORE replying to the GETDC or
SAMLOGON request.

this puts UDP port 138 into the category of... yes, you guessed it:
asynchronicity time!

i will work out whether this is _required_ or just pretty-looking stuff,
by simulating the delay.  hmm... doesn't work.  2 second delay is too
much.

*sigh*.  ok, this is where we REALLY get the fine-tooth-comb out, and go
over EVERY single damn packet in a 500-frame trace.

argh.