[9fans] Plan 9 system behind firewall

[kokamoto@hera.eonet.ne.jp]

I have two sets of Plan 9 system within different IP domain, one of which
is sitting behind the firewall made by a brordband router and using fossil+venti+
auth/cpu server and terminals(Plan 9-1).
Another is using Ken's fs, standalone auth server, cpu server, and terminals
(Plan 9-2).

When I use drawtrerm for Wn XP (belong th the same domain as Plan9-2),
it does work fine by such the command as drawterm -a 'IP of auth server'
-c 'IP of cpu server(=auth server)'.  It's fine, no excess time are neccessary,
just done within 30 seconds.   ---fact 1

Then, I tried drawterm for linux (newest stable Debian actually) as the same
command also from the outside of the Plan 9-1 domain.   In this case,
I have to wait 3 to 4 minutes until loging in the cpu server behind the firewall.   ---fact 2

Then, I tried to use the Plan 9-1 system from another Plan 9-2 system I have.
First, I made 9fs from a terminal of Plan 9-2 to the cpu server of the Plan 9-2,
and got good success.
This was done also withing 30 seconds.
I have a line of
auth='machine name of the broadband router' authdom='auth domain of that
Plan 9 system behind the router'
in /lib/ndb/local file on the Plan 9-2 system.   ---fact 3

Lastly, I tried to login to the Plan 9-1 system behind the firewall from the above
Plan 9-2 system, and now I have problem.   When I booted the Plan 9 kernel from
floppy drive (the kernel was read from the Plan 9-2 standalone auth server),
I had to wait 5 minutes until some response from the Plan 9-1
auth server behind the firewall.  It asked password, and I typed it, then,
I can reach the CPU server, not the Plan 9 system.  I suppose this is same as
cpu command, and then, I have no display for rio.   ---fact 4

questions:

Why I can 9fs but not login?
Why such a long time were necceessary for Linux and Plan9
to get factotum responce?
What is different between drawterm and ordinal login mechanism?

Thanks in advance,

Kenji  --now in big confusion