StJohns@SRI-NIC.ARPA (Mike StJohns) (08/28/87)
The subject says it all. Is there a public domain SLIP server for a 4.2 based system available anywhere? I've got a bunch of IBM PCs I want to run over something called a CO-LAN (wire replacement system). Mike
karels%okeeffe@UCBVAX.BERKELEY.EDU (Mike Karels) (08/30/87)
I'm not sure what you mean by a SLIP server; the SLIP protocol for the 4BSD side of a connection is included in 4.3 as if_sl.c. It is configured into a kernel with a line like pseudo-device sl 4 in the system config file, where the number is the number of lines to support. The lines are then set up with the programs slattach and ifconfig, each of which have manual entries. These programs are designed for more-or-less static configurations, as they don't allow dialup use (very easily) and don't do dynamic address assignment. The original versions of slip and slattach were written for 4.2BSD, and they are probably still available somewhere. Of course, you'll need a corresponding protocol module for the PC end, along with IP/TCP support; if that's what you're asking for, I don't know where to find it. Mike
STJOHNS@SRI-NIC.ARPA (08/30/87)
Thanks for all the responses. To summarize: SLIP comes embedded in 4.3. A version for 4.2 is available from seismo.css.gov or from mimsy.umd.edu. (BTW, seismo didn't seem to have any public access ftp files when I checked last night!) PC SLIP is available from SIMTEL20 or from MIT. Mike
rick@SEISMO.CSS.GOV (Rick Adams) (08/30/87)
You can ftp the source code for SLIP from uunet.uu.net as the file ~ftp/pub/sl.shar.Z This file contains the code for 4.2bsd systems and Sun 3.X. If you have 4.3bsd, you already have SLIP (it is surprising how many people ask this). It is known to run on vaxes and suns. It may run on other systems depending on how much the vendor "fixed" that wasn't broken. Note: SLIP is ONLY a device driver. You have to come up with your own IP, TCP, ICMP, ETC To answer the other popular question, no there is no RFC describing the "protocol" (I hesitate to call it a protocol. Its a simple framing scheme.) ---rick f
phil@amdcad.UUCP (08/30/87)
In article <8708300016.AA04771@okeeffe.Berkeley.EDU> karels%okeeffe@UCBVAX.BERKELEY.EDU (Mike Karels) writes: >I'm not sure what you mean by a SLIP server; the SLIP protocol for >the 4BSD side of a connection is included in 4.3 as if_sl.c. It is >configured into a kernel with a line like > pseudo-device sl 4 >in the system config file, where the number is the number of lines to support. >The lines are then set up with the programs slattach and ifconfig, each >of which have manual entries. This brings up a question I had. I hope it's not too stupid. Consider a network with machines A, B, and C. B talks to A and C. A does not talk to C except through B. B's /dev/ttyh0 goes to A. B's /dev/ttyh1 goes to C. I slattach ttyh0 and ttyh1. Now I want to ifconfig sl0 and sl1. How do I know which dstaddr to associate with sl0 and which with sl1? Does it matter? If not, how does the kernel know which tty line to send the packets down? The thing that confuses me is I would expect slattach to take a sl0 or sl1 argument as well as a tty argument. But it doesn't. Also, do I have to do anything special to B to get it to forward packets from A to C? -- I speak for myself, not the company. Phil Ngai, {ucbvax,decwrl,allegra}!amdcad!phil or amdcad!phil@decwrl.dec.com
kre@munnari.UUCP (08/30/87)
In article <18137@amdcad.AMD.COM>, phil@amdcad.AMD.COM (Phil Ngai) writes: > Now I want to ifconfig sl0 and sl1. How do I know which dstaddr to > associate with sl0 and which with sl1? Does it matter? If not, how > does the kernel know which tty line to send the packets down? It matters, and this has been bugging me too. The only way to solve this currently is to run all the slattach's serially, which means that if there's no carrier on the first (the remote end is down when you're booting) the second doesn't happen until carrier appears (who knows how long). It happens that its trivial to fix this, with no major changes to anything. Rather than tell slattach which slN it should use, we can just have it tell us which one it was assigned, then /etc/rc.local can look like UNIT=`slattach ttyh0 9600` dstaddr $UNIT ... # if needed ifconfig $UNIT ... All the support needed for slattach to do this is there already, I'm going to add the few lines needed (there will probably be a flag to cause this behaviour for backward compatability) sometime very soon now. I'll post the diffs. kre
ddp+@ANDREW.CMU.EDU.UUCP (08/31/87)
>PC SLIP is available from SIMTEL20 or from MIT.
Sorry Mike, but PC "SLIP" is not available from MIT. The "slip" which MIT
distributes does not support the same framing scheme as the "slip" (SLIP)
available with 4.3bsd. However, both the MIT slip and "SLIP" are included
with CMU-PCIP, available from me. It is also supported by the KA9Q (Phil
Karn) PC IP package.
Drewbeadel@oswego.UUCP (Edward F. Beadel, Jr.) (08/31/87)
Mike Karels writes (among other things regarding SLIP): > >of which have manual entries. These programs are designed for more-or-less >static configurations, as they don't allow dialup use (very easily) >and don't do dynamic address assignment. The original versions of slip Does anybody know of a 4.3( or 4.2)bsd version that has been hacked to allow dialup use? We are having "campus political problems" getting a dedicated 9600 baud line to another building that will connect through the SUNY InterCampus Data Network to NYSERNet and thus to the INTERNET. However we can buy a pair of 9600baud modems and dial up a phone that is right next to our on campus SICDN port. Of course the 9600baud modems are more expensive, however they seem to be the only way for now (sigh .......) We'd *LOVE* any help at this point since we don't have the time to hack it ourselves at this point in time. (Most of our Systems Programming effort is in beta 2.10 at present). Thanks, Ed ****************************************************************** Edward F. Beadel, Jr., Manager {seismo|decvax}!rochester\ Instructional Computing Center allegra !rocksvax!oswego!beadel SUNY College at Oswego {ihnp4|research|allegra}!warrior/ Oswego, NY 13126 (315)-341-3055 {allegra|watmath}!sunybcs/
ccruss@ucdavis.UUCP (Russ Hobby) (09/01/87)
Here at UC Davis this summer we have been working on a project to allow
PCs to make dialup SLIP connections to the campus IP network. We are
also working on abbreviated serial line IP (ASLIP) packeting that will
make dialup IP networks more efficient.
Here is how the system works. The user logs on to the host that is
acting as the gateway, a 4.3 bsd system. He then types in the command
"slip" and he becomes a host on the network. He can then use all the
programs that come with the CMU/MIT PC/IP or Phil Karn's system. To make
connecting to the network a little easier, we have written a program
that will do the complete login automatically. The program has a user
configurable script file that specifies a sequence of strings to send
out the serial line and responses to wait for comming back. It has its
own simple language with branching depending on if the correct response
came back. The net result is that after the script has been set up, the
user types in one command on the PC to connect to the network.
Unlike some PC/IPs, our system assumes that each PC (or actually each
user) has its own, permanent IP address. Security is provided by logon
security on the gateway host. The IP address of the PC is associated
with the usercode on the gateway host. The network connection for that
PC's IP address can only be started from a user logged in with the
correct usercode. The system also makes sure that the IP address is not
already connected before making a new connection.
The way we have set up IP address for the PCs is to have a separate
subnet that contains all the PCs. This way the gateway host needs only
to advertise that it is a route to that subnet and all the PCs are
covered. In essence the gateway host is the network for all SLIP
connections on that subnet.
The abbreviated packets work on the assumption that the connecting
computer is an end-node and will not be doing any routing. In this case
many of the fields in the IP packet are unnecessary. ASLIP uses the
minimum header size based on this assumption. With ASLIP the header size
is either 8 or 4 bytes, much smaller than the standard 40 bytes. The
host that is acting as the ASLIP gateway rebuilds the outgoing packets
to legal IP packets before sending them out the network and abbreviates
the incoming packets from the network.
The login capabilities are currently working. I frequently connect my
PC at home via dialup modems( one command "netcon") and use telnet,
ftp, whois and smtp. Code for ASLIP is now being written and hopefully
will be done by the end of September. At that point we will package up
everything necessary to make it work and it will be available to anyone
that is interested.
Also there have been some terminal server vendors interested in this
project. It should not be much work to turn a terminal server into an
ASLIP or SLIP server and that would make it cheaper than using a VAX as
the gateway. Plus there would not be as much maintainance and downtime
with a simple server box.
This Fall's project is to take the best of CMU's PC/IP, Phil Karn's IP
and Stanford's PC/IP and make a PC package that has the networking
interface and services(SMTP,FTP...) running in the background. Client
software will run in foreground but will use the background interfaces
for connection to the network.
Russell Hobby
Data Communications Manager
U. C. Davis
Computing Services BITNET: RDHOBBY@UCDAVIS
Davis Ca 95616 UUCP: ...!ucbvax!ucdavis!rdhobby
(916) 752-0236 INTERNET: rdhobby@ucdavis.ucdavis.eduzeeff@b-tech.UUCP (Jon Zeeff) (09/08/87)
In article <8708300436.AA03739@beno.CSS.GOV> rick@SEISMO.CSS.GOV (Rick Adams) writes: > >Note: SLIP is ONLY a device driver. You have to come up with >your own IP, TCP, ICMP, ETC > So it seems that to use 4.xbsd machine as a slip server (ie. I want a 4.x machine to talk to a PC via slip, giving a PC network access), there would be some simple software needed to pass packets from the slip driver to the regular ip driver. Has anyone written such software? >To answer the other popular question, no there is no RFC describing the >"protocol" (I hesitate to call it a protocol. Its a simple framing >scheme.) Perhaps there is some other documentation of the framing scheme? -- Jon Zeeff Branch Technology, uunet!umix!b-tech!zeeff zeeff%b-tech.uucp@umix.cc.umich.edu