Here is the alt.dcom.slip-emulators FAQ.  All original authors are left in,
I've added my own comments/additions within [ -Dan].


Newsgroups: alt.dcom.slip-emulators
Path: msunews!caen!spool.mu.edu!howland.reston.ans.net!ix.netcom.com!netcom.com!stevew
From: stevew@netcom.com (Steve Wilson)
Subject: alt.dcom.slip-emulators FAQ V1.2
Message-ID: <stevewDBnqGB.A02@netcom.com>
Summary: Alt.dcom.slip-emulators FAQ V1.2
Keywords: FAQ 
Organization: NETCOM On-line Communication Services (408 261-4700 guest)
X-Newsreader: TIN [version 1.2 PL1]
Date: Thu, 13 Jul 1995 13:50:34 GMT
Lines: 793
Sender: stevew@netcom21.netcom.com

Alt.dcom.slip-emulators FAQ  V1.2   Jan 11, 1995

In our latest release of the FAQ there are actually posts about
OTHER than slirp!  I'll probably try to collect things by topic
in the next release and actually add a table of contents for the
questions... but that'll be the next release ;-) I've only got
a few minutes right now to mess around..and it had been awhile..
so...

Steve Wilson


----------------------------------------------------------------------------
In article <waddell.803517481@hercules>, waddell@HERCULES.CS.UREGINA.CA 
says...
>
>Is SLiRP free to use (ie.  will I be charged long distance fees for using
>this because it uses my modem> or does it use the University's (or Unix 
>server's modem>?
>

Yes. SLiRP is a free copyrighted software.  SLiRP runs on your UNIX shell 
account and let's you connect to the internet.  You need a client PC with a 
TCP stack like Trumpet Winsock which uses your modem to access your shell 
account.  If there is a long distance charge to access your university's 
computer, then you will have to pay those charges, as well as, any usage fees 
that you are now paying.  Otherwise, you don't have to pay for accessing the 
internet.

Hope this helps,

Lynn
-- 
Lynn Larrow        "When the shoe fits, the foot is forgotten"
Systems Engineer                   Chuang Tzu
llarrow@netcom.com                                Pacific Grove, CA
http://www.webcom.com/~llarrow/tiarefg.html (SLiRP/TIA/Trumpet Setup)
[Editor's note:  The above is a VERY useful home page, and is packed
 with more info than you'll find here!!]
----------------------------------------------------------------------------

Leo Perez y Perez (perez@csulb.edu) wrote:
: Is SLiRP better as SLIP or PPP?
: or, what is the difference between them anyway?
:
: --
: Leo Perez y Perez    
: perez@csulb.edu      

There are really three protocols available with slirp.

They are SLIP, CSLIP, and PPP.

The protocols have the following properties...

Slip is merely raw IP frames sent in between two Flag characters, one
indicating start, and the other indicating end of packet.  There is
an escaping method when either of the two flags appears inside the 
actual IP datagram.

CSLIP is sent via the same basic mechanism over the physical medium(your
phone line) but an added level of compression is applied to the 
header of the IP datagram itself such that the IP header is reduced
in sized from something like 40 bytes to something like 7 bytes.  This
savings happens on EVERY packet.  This is a style of compression that
is beyond the V.42bis compression algorithm used by your modem.  Estimates
give about a 20% increase in performance(give or take 10%).

[VJ compression brings the header from 40 bytes to an average of 3-4 bytes.
While it is desirable, and does increase the performance, it can also be bad
on error-prone links because a) it hinders fast-recovery, and b) when one packet
is corrupt ALL subsequent packets are corrupted until that first one that
was corrupted is re-transmitted.  Note also that UDP packets, and "unusual"
(in the sense that it doesn't happen often) packets and retransmitted
packets are not compressed.  -Dan]

PPP (or Point-to-Point Protocol) really might be classified more like
a byte oriented HDLC.  That means that it takes the IP datagram and puts
inside yet another encapsulating packet.  This packet has a CRC across
it so bad packets can be detected at the lowest level.  There are also
security features built into this protocol.  Basically, it is a far more
robust protocol than Slip or CSLIP.  PPP also has the added property that
the Slirp implementation can escape several control characters, so you
are more likely to get a successful link up on a line that isn't 
8 bit clean. (aka a serial line that has some sort of input processing
occuring.) 

From previous performance measurements, people have found that CSLIP
is fastest when using Slirp.  Some folks(like me) wind up using PPP
over CSLIP because of the need for the escaping feature. In my case
this allows me to do ftp sessions that don't work under CSLIP.

Now, that is probably more than you ever wanted to know ;-)

Steve Wilson

[PPP is the best choice.  Not only does it have true "link up" and "link
down" states, it also autoconfigures the IP's etc.  As for performance, PPP
also does VJ compression (like CSLIP does) and so has, at best, 3 bytes per
frame (1 byte for the protocol, 2 bytes for the FCS (Frame Check Sequence))
more than CSLIP, provided both ends agree on the protocol/address/etc.
compression.  Also, because of the FCS, it can also be more efficient
because it will detect errors at the PPP layer and can tell the VJ code
about it, for example.  If your link is 8bit clean, make sure you put
"asyncmap 0" in your config files (on both ends preferably), as all control
chars are escaped by default  -Dan]

----------------------------------------------------------------------------

In article <ekbondDACC0q.DFM@netcom.com>, ekbond@netcom.com (E. Kelly
Bond) wrote:

> Is it possible to send mail from my Linux box to/through Netcom
> while connected via TIA?
> 
> Any help will be appreciated.
> 
> Kelly
> ekbond@netcom.com

Yes, I am doing it.  You have to configure your domain name to netcom.com
and use sendmail with the smtp-only script in /usr/src/sendmail/cf, and
all will be great.  There are readmes in the sendmail directory how to use
m4.  It's a one liner.  Use sendmail -q to bump the queue into action when
you connect, or as part of your ppp-on script.

Oh, actually I am doing it with SLiRP, not TIA, but same thing...

Cheers,

-- Grant Bowman     <grantbow@netcom.com> 
----------------------------------------------------------------------------
In article <3s35j8$eab@gulfa.kuwait.net>, kcc94td1@access.kuwait.net says...
>
>Hi guys,
>
>Anyone know where there are pre-compiled SLiRP binaries?  This would be 
>very helpful and highly appreciated :-D
>
>Thanks in advance
>
>Khaled al-Feeli
>Kuwait Computer company
>

Try ftp://ibc.wustl.edu/pub/slirp_bin/USE_AT_OWN_RISK/

I also have some other links to slirp binary sites at this URL:

http://www.webcom.com/~llarrow/tiafaqs.html

Hopefully they are all still active :)

Lynn Larrow        "When the shoe fits, the foot is forgotten"
Systems Engineer                   Chuang Tzu
llarrow@netcom.com                                Pacific Grove, CA
http://www.webcom.com/~llarrow/tiarefg.html (SLiRP/TIA/Trumpet Setup)
----------------------------------------------------------------------------


In article <frankDAGH97.Gu6@netcom.com> frank@netcom.com (frank) writes:
>Hi, Slirpers:
>
>How do I telnet into my linux box?  I redir the port 8888 to 192.0.2.0:23
>I am using SLiRP 0.9o.  But when I login to netcom and use
>telnet netcom8(or whatever).netcom.com 8888, nothing happened.
>Do I need to set my IP to 192.0.2.0 instead of 10.0.2.15?  Any help
>will be greatly appreciated.
>
>frank@netcom.com


Why don't you try redirecting it to 10.0.2.15:23  ???

----------------------------------------------------------------------------
>                           LATEST INFORMATION
>                  --------------------------------------
>
>  *  (21/6/94) I think I finally fixed the "locking-up" problem. Edit the
>    file tcp_input.c and uncomment the lines:
>    /* if (so->so_snd.sb_cc)
>    * (void) tcp_output(tp);
>    */
>    This means you can use a low RWIN again, and still have it work (I
>    hope).
>  *  (5/6/94) Get version 0.9o, it should fix the nasty SunOS problem, as
>    well as others. This will be the last release for around a month or
>    two (provided I find no major bugs (again)), since a) I have tests
>    coming up, and b) I'm planning big changes/additions to slirp for the
>    next release (It'll probably be a BETA release, finally).
>
>  [Back To SLiRP Home Page] [Features] [danjo@blitzen.canberra.edu.au]
>
>                Copyright ©1995 Phase One WWW Publishing

I tried out the code change and it seems to be working fine for me.

I am now able to reduce my RWIN in trumpet back to 4 times my MTU and I have no lockups.

    o      _____         ||Jose Barandiaran | |joseb@twisto.compaq.com  |
----------------------------------------------------------------------------
In article <stew1117DAJ8vy.96s@netcom.com>,
>stew1117@netcom.com (stewart coulter) wrote:
>I am trying to locate the latest version of slirp, the one site that I 
>tried I was unable to locate it any directories, please help me.  I need 
>the FTP site and directory.  Respond via email.

Folks on Netcom can get the release files and a few other doo-dads from my 
directory:

  ~ldobbs/slirp

The modified source for tcp_input.c (see other threads) is there, along with 
some simple (and undocumented) scripts to build the binary.

Lee Dobbs                     Milpitas CA            Voice: 408-946-7860
ldobbs@netcom.com                 USA                Fax:   408-262-9392

----------------------------------------------------------------------------
sterns@rahul.net (Steven Stern) wrote:
>Hi,
>    I'm running Win95 (build 484) and just tried to run the 32 bit
>version of Netscape with no luck. I can't get DNS lookup to work.
>
>Is this combination possible or will it not work because Trumpet is
>not a 32 bit application ?
>
>BTW the 16 bit version works just fine !
>
>Steve
>                                                               ~~~
>                                                              (o o)
> ----------------------------------------------------------ooO--U--Ooo-----
> Steven Stern           email: sterns@rahul.net     


It seems that the 32-bit version of Netscape cannot communicate 
with a 16-bit TCP/IP stack.  However, you don't need to use 
Trumpet anymore.  Just use SLiRP with the -P or ppp option (for 
Point-to-Point Protocol).  On the Windows 95 end, you'll need 
to go into Dial-Up Networking in My Computer and define dialer 
"objects" for each of the numbers you wish to call on your 
server.  The default protocol is PPP and is set under Server 
Type.  You'll then need to set up a dummy IP address in either 
Network under Control Panel or on the object itself, if your 
build of Windows 95 supports that (which I think 484 does).  
There are a few other things, such as Name Servers and 
Gateways, but since you've already set up Trumpet, you'll know 
what to put in there.  You'll want to specify that Windows 95 
bring up the terminal window after dialing so that you can 
enter your login information.  This can be done in Server Type 
as well.  Don't worry about the login name and password in the 
dialer object; it can't be resolved anyway and you'll connect 
just fine when you enter it in your terminal window.  After 
entering your user ID and password and finally the SLiRP 
command line, you simply press F7 (Continue) and you're all 
set.  All of your winsock apps will work, 32-bit and 16-bit.

If you have any trouble setting this up, let me know. Maybe I 
can help.  Just short on time at the moment.  
mailto:davidb@mordor.com
----------------------------------------------------------------------------
whoa@netcom.com (arlene agcongay) wrote:
>
>hi, i just got SLiRP working for me the other day, but i have a
>question.  I'm using OS/2 Warp with SLIRP, and when i start it up,
>it tells me that my baud rate is 1200.  I would like to configure
>this part to a higher baud rate, but i don't know which file to
>edit.  What i've been doing is opening up another comm software like
>ZOC and have it initialize my modem to 38400.  but there has to be
>an easier way!  i'm a newbie to this, so please help me.. =)
>
>thanks in advance!!
>
>
>-arlene
>
>

slirp -b 38400  will tell SLiRP to send and receive data from 
your provider's modem at 38,400 bits per second.  To receive 
the data at the fastest possible rate, you'll need to call a 
number that supports the highest transmission rate possible 
with your modem and be sure you are connecting at that speed.  
What concerns me is that SLiRP defaults to 9600 "baud" and 
should not be reporting 1200 unless you have explicitly 
requested it with the -b switch. Maybe you are misreading one 
of the other parameters, such as MTU?

db

----------------------------------------------------------------------------
Tanvir Ul Haq (ulhaq@seas.gwu.edu) wrote:
: In article <3schd8$cs3@ccnet.ccnet.com>, rampage@ccnet.com (Rampage) wrote:
: >This is driving me crazy.. what is the .slirprc syntax to say, run your 
: >unix shell using slirp.telnetd .. no one can answer this for me, it seems 
: >and I haven't been able to find any documentation on the subject.. it's 
: >rather frustrating. Thanks. E-Mail Please.
: Me too please!
:
: Tanvir Ul Haq

Put a line in your .slirprc indicating what shell you want, eg>
shell /bin/csh

...then make sure slirp.telnetd is in your PATH env - i placed mine in 
~/bin/ and dont chaange its name from slirp.telnetd

Ok now when you have your pseudo-slip dialed in, you can start an app like
'Trumpet Telnet' and type in 10.0.2.1:23 as the ip to connect to (if you 
kept the default local ip). It will connect to the host machine without the
 need for logging in - this remote shell you now have wont show up as another
 entry on a 'who' or 'w' listing.

Hope this helps,
 James

----------------------------------------------------------------------------
[ Editors' note: I screwed up the request below...so added the one line
  to get the context of the original question back.. Sorry 'bout that.]
>How does one get to a 
>unix shell using slirp.telnetd .. no one can answer this for me, it seems 
>and I haven't been able to find any documentation on the subject.. it's 
>rather frustrating. Thanks. E-Mail Please.
>
>--
> ______  
>( ____ \  rampage@ccnet.com	http://www.ccnet.com/~rampage	net-geek

	Simple, in your .slirprc you have a line such as is mine for tcsh:
		shell /usr/local/bin/tcsh
Then (if 10.0.2.0 is your SPECIAL address as it is for me) you telnet from your
local machine to 10.0.2.1 to get a 'shell' on your remote machine.  In my case
I put a lines in /etc/hosts such as:
		10.0.2.0 slirp
		10.0.2.1 remote
so that I can 'telnet remote' to get a shell or 'telnet slirp' to talk to
SLiRP's command line.

rdt
                                                   mailto:rdt@realm.net    
                                               or  mailto:rdt@kaiwan.com   
----------------------------------------------------------------------------
SLiRP has become stable and the lock-up bug was finally fixed(?).
I think it's time for new benchmark test on TIA and SLiRP. 

(*** Well, seems like I will have to do another test in 2 weeks. 
TIA 2.0 beta will be released in next month. I just got new TIA news.)

Anyway,

I performed a small benchmark test using ws_ftp. The method used is mostly
the same as the previous test I did and posted here few month ago.

I transferred file between UNIX host and local PC over serial line three
times in each direction and averaged the speed (in Kbps).

This time I could use the same Trumpet setting for both TIA and SLiRP,
which means you can compare data of the two directly. Also, I used
both compressed and non-compressed files in the tests.

Let's show you the result first.


WS_FTP.EXE (150944 byte, a binary executable)
=============================================
	TIA	SLiRP
	SLIP	SLIP	CSLIP	PPP
---------------------------------------------
Downld	18.06	17.31	18.53	18.45 (Kbps) 
Upload	18.94	18.88	19.35	19.30
=============================================

WS_FTP.ZIP (117641 byte, ZIP compressed)
=============================================
	TIA	SLiRP
	SLIP	SLIP	CSLIP	PPP
---------------------------------------------
Downld	15.87	14.97	16.24	16.14 (Kbps)
Upload	16.36	16.32	16.70	16.66
=============================================

What do you think? It's interesting, isn't it?

* Actually, the result is not much different from the previous test.
In the previous test, I used MTU of 552 for Slirp and I thought it
made Slirp slower than TIA. However, Slirp is still slower than the
TIA in SLIP. Slirp gave me *really* good result in CSLIP and PPP. 
CSLIP is slightly faster than PPP but I think the difference has 
become small. (Acutually, I lost the old result. ^^; Am I telling 
you the truth?)

* As a result of tcp_input.c fix, Slirp now works even if you don't
use Passive mode in ws_ftp. However, you should always get faster
transfer if you use Passive mode. This applies to TIA, too.  

 
#####
Here's hardware and software information:

UNIX  -- SparcSun-4/280. SunOS-4.1.3
PC    -- Toshiba T3400, i486SX-33MHz, 4MBram, Windows for Workgroups.
Modem -- US Robotics WorldPort 14.4K PCMCIA Fax/Modem.

WS-FTP version 95.06.11
	Recv Bytes 4096
	Send Bytes 1500
	*Passive Mode* is used in all transferres.

Trumpet Winsock version 2.1b 
	MTU 1500, RWIN 4096, MSS 1460.
	Baudrate 38400

TIA version 1.04c (beta)

Slirp version 0.9o (tcp_input.c fixed)
			[.slirprc]
	SLIP		CSLIP		PPP
	************** 	**************	*****************
	Baudrate 38400	Baudrate 38400	Baudrate 38400
	mtu 1500	compress	ppp
	mru 1500	mtu 1500	mtu 1500
			mru 1500	mru 1500
					asyncmap 00000000
	**************	**************	*****************


*** All Data ***

## TIA ##
[SLIP]	ws-ftp.exe			ws-ftp.zip
--------------------------------------	------------------------------
	Down		Up		Down		Up
	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)  
--------------------------------------	------------------------------
1.	81.8	18.08	78.0	18.95	72.6	15.88	70.4	16.37
2.	82.0	18.04	78.1	18.94	72.9	15.82	70.5	16.35
3.	81.8	18.08	78.2	18.92	72.5	15.90	70.4	16.37
--------------------------------------  ------------------------------
Ave.	81.9	18.06	78.1	18.94	72.7	15.87	70.4	16.36
--------------------------------------	------------------------------

## SLiRP ##
[SLIP]	ws-ftp.exe			ws-ftp.zip
--------------------------------------	------------------------------
	Down		Up		Down		Up
	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)  
--------------------------------------	------------------------------
1.	85.6	17.28	78.4	18.88	77.3	14.92	70.7	16.31
2.	85.5	17.31	78.5	18.84	77.0	14.98	70.6	16.32
3.	85.4	17.33	78.2	18.91	76.8	15.02	70.6	16.32
--------------------------------------  ------------------------------
Ave.	85.5	17.31	78.4	18.88	77.0	14.97	70.6	16.32
--------------------------------------	------------------------------


## SLiRP ##
[CSLIP]	ws-ftp.exe			ws-ftp.zip
--------------------------------------	------------------------------
	Down		Up		Down		Up
	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)  
--------------------------------------	------------------------------
1.	79.8	18.53	76.4	19.36	71.0	16.24	69.0	16.70
2.	79.8	18.53	76.5	19.33	71.0	16.24	69.0	16.70
3.	79.8	18.53	76.4	19.36	71.0	16.24	69.0	16.70
--------------------------------------  ------------------------------
Ave.	79.8	18.53	76.4	19.35	71.0	16.24	69.0	16.70
--------------------------------------	------------------------------


## SLiRP ##
[PPP]	ws-ftp.exe			ws-ftp.zip
--------------------------------------	------------------------------
	Down		Up		Down		Up
	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)	(Sec)	(Kbps)  
--------------------------------------	------------------------------
1.	80.1	18.46	76.6	19.30	71.5	16.12	69.2	16.66
2.	80.3	18.42	76.6	19.30	71.4	16.15	69.2	16.66
3.	80.1	18.46	76.7	19.29	71.3	16.16	69.2	16.66
--------------------------------------  ------------------------------
Ave.	80.2	18.45	76.6	19.30	71.4	16.14	69.2	16.66
--------------------------------------	------------------------------

That's all. (Hope I didn't make any stupid mistake.)

Thanks.

---

Masa. <msato@calstatela.edu>

[Editors' note:  I think this one gets the best post of the week award!]
----------------------------------------------------------------------------
On Sun, 25 Jun 1995 08:34:57 GMT Steven Stern (sterns@rahul.net) wrote in alt.dcom.slip-emulators:
: I'm running Win95 CSLIP with Slirp at the other end. After I start
: Slirp I get the following msg:

: SLiRP Ready ... (autodetect SLIP/CSLIP, MTU 552, 9600 baud)

: I'm using a 14.4 modem. Does the message above really says I'm only
: connected at 9600 ?

: Before Win95 Cslip, I always got 14.4 connections with Trumpet !

: Please help !

You need to specify the baud rate on the command you use to start slirp,
like: 
      slirp -b 14400 -c

Ahmad
--
Ahmad Al-Nusif            | E-Mail: morpheus@kuwait.net                      |
-----------------------------------------------------------------------------
stew1117@netcom.com (stewart coulter) wrote:
>Hello, I am using Slirp version O, everything is running fine except the 
>news.  I have a netcom account and was told I need the file NNTPD, where 
>can I find this file and what type configuring do I have to do to the 
>slirp O program?  Please respond via email

From a directory in your path (probably either your home directory or ~/bin), 
do

  ln -s ~seligman/bin/nntpd

Or, if you want your own copy (just in case), do

  cp -p ~seligman/bin/nntpd .

This version, written by Scott Seligman, supports XOVER. The TIA version will 
also work with either TIA or Slirp. Find it at

  ~barryn/pub/nntpd

These are on Netcom, of course, since they're only needed to emulate a normal 
NNTP server with Netcom's disk-based equivalent.

To use this with Slirp, add the following line to your .slirprc file:

  add exec nntpd 10.0.2.1:119

unless you use the TIA-style addresses, in which case you'd add

  add exec nntpd 192.0.2.3:119

Lee Dobbs                     Milpitas CA            Voice: 408-946-7860
ldobbs@netcom.com                 USA                Fax:   408-262-9392
-----------------------------------------------------------------------------
D. Henry (marbling@apk.net) wrote:
: In article <3sj8cs$j3e@metz.une.edu.au>, jzhou1@metz.une.edu.au (JUN ZHOU) says:
: >
: >Hello,
: >
: >I am trying to run Netscape and Eudora on a PC with a modem. I have installed
: >the Trumpet winsock and can loging manually from TCPMAN widows. However, when 
: >I try to run the wisock applications, the Tcpman is lunched and minimized but
: >the Netscape windows never pop up.
: >
: >Any help is highly appreciated


He-he. I used to make the same mistake when I just installed Trumpet 
Winsock. Here's the catch. If you select 'Manual Login' option from the 
Trumpet Winsock's Dialler menu, SLIP is automatically disabled. After you 
manually log in and start your SLIP emulation, don't forget to press the 
'ESC' key. It will enable SLIP, and Trumpet Winsock will start talking 
to your SLIP emulator. If you don't do so, Netscape window will never pop 
up...
I hope this helps.

Regards,
Stan

----------------------------------------------------------------------------
In article <3t278g$46r@newsbf02.news.aol.com>,
rmpshaker2@aol.com (RmpShaker2) wrote:
>Hey guys, When I setup my network settings, my only server type is PPP. I
>don't have a PPP connection, I have a slip.  I tried configuring the damn
>thing, but I found NO option for slip anywheres. I went through all the
>help and found jack.  Does anyone know how to setup a SLIP?
>
>Thanks, Chris

Unfortunately Win95 does not automatically set-up SLIP protocol, but it's 
quite easy.

Go into control panel, then add/remove software, then Windows Setup, the Have 
disk, now browse for a file named RNAPLUS.INF, it's on the cd, in think in 
admin\apptools\slip, and that's it.  Now when you set up server you should 
have cslip and slip options

----------------------------------------------------------------------------
browe@netcom.com (Bill Rowe) wrote:
>In article <stevewDB8u3p.FIv@netcom.com>, stevew@netcom.com (Steve Wilson)
>wrote:
>>When you start up a shell, you tie-up a certain amount of memory
>>with local defines...like the path you use to search for commands,
>>any special "environment variables," etc.  If you fork off another
>>shell via telnetd, it will inherit this same environment...what
>>Lee is saying is that you probably just get a link to this stuff
>>instead of taking up X amount of more memory...
>
>Are you saying with telnetd the path to my home directory is not
>available? If it is available, how could it not be taking memory? If it
>isn't available, this seems to me a good reason not to use telnetd to
>access my shell account. 
>
>Usually, if I telnet to my shell it is because I want to manipulate one or
>more files there. Lack of access variables which are defined at login such
>as $PATH would seem to make it significantly more difficult to do the
>usual things with a shell account.

All the environment variables that were set by your login shell process 
*are* available to any subprocess. If the subprocess happens to be another 
shell, any reference to an unmodified environment variable just points back 
to the memory block attached to your login process. So, things like your 
path, term, prompt, shell, etc., don't have to be recopied -- they're 
already available.

The situation is different, however, when you start up a shell from an 
intermediate process like telnetd. telnetd doesn't pass the environment 
variables to the shell, so it starts up with just the default subshell 
parameters. You have to tell it to do something extra. If your shell is one 
of the csh derivatives, you need to tell it to execute your .login file in 
addition to the usual .cshrc file. One way to do this is 

  exec csh -l

which replaces the original telnet shell process with another one, but this 
time reading the .login file first. There are equivalents for the Bourne 
derivatives so that it executes your .profile first, but I don't remember 
what those are right now.

By the way, the shell variables are only part of the environment memory 
usage. There is some environment memory dedicated by your host to keep track 
of your login process and all your subprocesses. This includes space for:

 All the open files
 Access rights to files and processes
 The working directory
 The file creation mask
 Values of resource limits
 Signals to be ignored by the parent
 Signals not to be ignored by the parent

That's why it's still better for the host if you use a subshell through 
telnetd and then set your PATH, etc., than if you start a completely new 
login session.

Does this help? Are we having fun yet? :)

Lee Dobbs                     Milpitas CA            Voice: 408-946-7860
ldobbs@netcom.com                 USA                Fax:   408-262-9392
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In article <DB9Hwz.BDL@agora.rdrop.com>, lucasa@postes.gaylord.org says...
>
>Hi all!
>Could someone please inform me of a FTP site for the 
>updates to slirp?
>I would appreciate it.....
>Thank you
>Lucas

ftp://peace.wit.com/danjo/slirp/  or
ftp://blitzen.canberra.edu.au/pub/slirp/  or
ftp://ibc.wustl.edu/pub/slirp_bin/

Lynn Larrow        "When the shoe fits, the foot is forgotten"
llarrow@netcom.com                                Pacific Grove, CA
http://www.webcom.com/~llarrow/tiarefg.html (SLiRP/TIA/Trumpet Setup)

----------------------------------------------------------------------------
wmcbrine@clark.net (William McBrine):
> FTP-PM never connects when I use it under SLiRP. Pretty much everything 
> else works fine, including FTP and NcFTP, except of course ping. What's 
> the problem, and is there a fix?

Well... You actually stated the problem yourself. Ping soesn't work,
and FTPPM uses PING. You can tell the IAK that PING is not available
by remarking the line starting with "icmp" in the file "protocol"
thats the fix).

/Jonas
Jonas Eckerman                    FSDB
jpe@algonet.se    www.algonet.se/~jpe/

----------------------------------------------------------------------------
In article <DBDL0D.Ltu@dorsai.org>, Mike Russo <stardate@dorsai.org> wrote:
>At least, that's how I got TIA to work. I hope either TIA 2.0 or the 
>next SLiRP will support this protocol, along with PPP (and maybe automatic 
>port redirection? in my dreams?) =)

PPP is in TIA 2.0 (as is CSLIP).  It is working even as I type this,
but we've not released TIA 2.0 yet, so I can't say more at this time.

The others are tough nuts to crack, so let me address them one at a
time.

The ICMP protocol is simple and easily implemented.  However, there is
one minor problem (or major depending on who you are): root access.
ping must be run by root to work (or be setuid uid 0).  TIA or SLiRP
would need to be installed setuid, which violates one of the prime
assumptions that at least TIA has: No extra ordinary privs should be
required to use TIA.  So ICMP could be implemented for the link, but
not forwarded to other machines.  TIA 1.x doesn't choose to do this.
TIA 2.0 likely won't either.  Creative solutions to this problem may
be possible, but I've not had time to fully investigate my ideas, so
I'll not speculate on them just now.

Automatic port redirection is also hard.  When the TIA client[*] has a
program that wants to listen on a port, nothing happens over the wire.
Sure, buffer space gets allocated, the TCP stack's internal data
structures are setup, but no packets are sent over the link.  Since no
data flows accross the link, TIA (and SLiRP) have no way of knowing
that you desire to have a server or do port redirection.  Also, if TIA
or SLiRP were to try to do this, how could it inform you of the ports
that it chose for the servers you wish to run?  How would you know you
needed to connect to port 8456 to connect to your FTP server?  That's
why you need to tell TIA (and SLiRP) how to redirect the ports.

I wish I could have told you that TIA 2.0 solves all the hard problems
that exist in your dream product, but I can't because some of them are
very hard nuts to crack.

[*] A TIA client is the machine at the end of the point to point link
    that isn't running TIA.

Warner Losh		"VMS Forever"		home: imp@village.org
Cyberspace Development, Inc			work: imp@marketplace.com

[An easy solution is to "emulate" ICMP with UDP packets... when an ICMP ECHO
arrives, send a UDP packet to the echo port and when it's received, send the
ICMP ECHO REPLY back to the local-host.  There is one major hurdle though:
lazyness.  I beleive there are major breakthroughs in medically treating
lazyness, but that's beyond the scope of this FAQ :) (also, this would be
too much work for very little gain.  the solution is too simple: don't use
ping.  when it's emulated, you won't have a real ping, so why bother?
simply telnet 10.0.2.1 and use the system's ping/traceroute/whatever) -Dan]


----------------------------------------------------------------------------
In article <DBD1MG.6J5@zeno.fit.edu>, lkhan@winnie.fit.edu says...
>I have installed the latest version of slirp on the Unix machine.  It
>conplied properly (although I had to erase some files so it won't go over
>disc quota).  Using Trumpet Winsock, I ran it using the command line:
>"slirp -m 552 -c" (I set all the configurations as stated on the slirp home
>page.)  It shows all the messages at the beginning expect for the dns ip
>address.  So I used the "I.P. address of slirp" for the dns.
>
>When running Mosiac (ver. 2beta4), it wouldn't load the homepage.  The 
>messages at the bottom stop at "Waiting..." and sticks there forever, the
>little Mosaic "earth" still moves.
>
>What can be wrong??
>
>On the same machine, I can still run twinsock properly (it works.)

My best guesses would be one of two things.  The first is that using the IP 
address of the machine slirp is running on as your DNS isn't working.  In many 
university situations, they will have one or two machines which serve as 
nothing more than DNS servers.  You need to find out the address of these 
machines.  The best idea here would be to ask the sysadmin at your site.

The second good possibility is that a terminal server is interfering.  Using 
SLIP/CSLIP requires an absolutely clean 8-bit line, something that most 
terminal servers in a university setting have trouble with.  Try to find out 
if your terminal server has a 'terminal download' option, or something similar 
to set the connection to 8-bit clean.  Alternatively, try using SLiRPs PPP 
mode as you can escape control characters which may help the problem.  BTW, 
this would explain why twinsock works as it defaults to a 6-bit mode, which 
means it can run over almost any connection.  It also makes it dog slow.

Hope this helps.

Matt
mnm@goodnet.com
matt.moore@asu.edu
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In article <3tqam6$lsv$1@mhafm.production.compuserve.com>, Jeff
Morganstern <102174.225@CompuServe.COM> wrote:

> Can someone explain to me why (from an annex type server) I can use 
> rlogin to my unix account and slirp works fine, but if I telnet 
> there, it does not?  I'm able to get into my (free but far away) 
> unix account through a local gopher server, but it can only telnet 
> there.  In order to use the rlogin protocol, I need to dial up 
> directly (expensive).  Is there any way around this?
> 
> Thanks.
> 
> Jeff

The reason is that rlogin is a much simpler program than telnet,
and is therefore more "transparent" in terms of not mucking about with
the characters that go through.

For SLiRP to work, you need a relatively "clean" 8-bit connection.
Telnet may do any or all of the following.

1. Strip out the eighth bit, leaving a 7-bit link.
2. Intercept certain characters, and translate them into telnet
   escape sequences.
3. Break the link if it receives certain characters.

That is not to say that it is impossible to get telnet to work.
Depending on the version of telnet you may be able to get an eightbit
link by either specifying it as an option (telnet -8), or by careful
settings on the machine you are telnetting from, for example,

stty -parenb                ; no parity, 8-bit characters
stty crtscts                ; hardware flow-control
stty -ixon                  ; no XON
stty -istrip                ; don't strip off eighth bit
                            ; what else?? mdmbuf?

You may also need to use PPP so that you can "escape" the characters
that would telnet would intercept.

[escaping ctrl-] (ASCII 29) and the telnet command character (ASCII 255)
should do it -Dan]

There may be other things that need to be done.  I've been able to get
a connection established with slirp through a telnet link, but have not
gotten it to work satisfactorily, whereas rlogin works fine.  Your results
may differ.

[rlogin will most probably need ~ escaped (ASCII 126) -Dan]

