2.9bsd tcp/ip

[Sung Chung]

A friend of mine in SNU(Seoul National Univ., Korea) is grappling
with 2.9bsd network.  They received the distribution from UCB a few
months ago.  While they were installing it, they found some header
files of tcp/ip missing.

So, here is some questions on the matter.  I would appreciate it
if you give me any answers to them.
Thanks in advance!

1.  If they get the missing sources, can it be installed without
    severe problems ?  Then, can you send me the missing files ?
    (Here is the list of missing header files:
	/usr/include/sys/
		ecreg.h, emreg.h, ilreg.h, mbuf.h, protosw.h,
		socket.h, socketvar.h, unreg.h
	/usr/net/sys/net/
		css.h, dmc.h, ec.h, un.h, vv.h
    )

2.  If you are using tcp/ip on 2.9bsd, can you tell me about 
     its performance and its overhead ?
    And what type of device is used on it ?

3.  What's the most recent version of 2.9bsd tcp/ip in public domain ?
    
4.  Where can they get the source, and how ?


Thanks.

-- Sung Kwon Chung

Arpa: sung at uw-june.arpa
Uucp: ...hplaps!tektronix!uw-beaver!uw-june!sung