From: peter@modtor.uucp (Peter Ziobrzynski)
Subject: Re: Slip/ISC2.2.1
Keywords: slip
Organization: Modular Research
Distribution: comp
Date: Sun, 12 Apr 1992 16:02:54 GMT

tim@sabus.UUCP (Tim Brown) writes:

>Can anyone provide me with detailed step by step instructions on how
>to setup slip on a 486 running isc2.2.1?  I have tried following the
>manual but the machine just crashes.  Before I start debugging isc's
>stuff again and waste tons of time I thought I would ask.

>Thanks.

I remember that after I bought the ISC OS I spent a lot of time trying
to figure out the SLIP configuration. Unfortunately the ISC manuals
do not give enough information to get this done.
I also think that the majority of the comp.unix.sysv386 community
(except Larry Snyder :-) is convinced that SLIP is dead on ISC.

I wonder why nobody from ISC never posted anything to help users in this area.

To change that conviction here is what you need to do to configure and
use this stuff:

1. Decide what is more important in your 2.2.x installation: NFS or SLIP.
You cannot run both. If you have NFS installed all attempts to
link SLIP STREAM modules into your IP stack will result in kernel panics.
If you decided for SLIP and have NFS installed - remove it and relink the
kernel.

2. You have to plan the topology of your network and networks that you
intend to connect over SLIP. A number of the configuration files
have to be tunned (local and remote) and this can be best done having
a chart of the planned connections. I use SLIP in the following environment:

The are two major sites that I connect to from my home i386/ISCi2.2.1 box.
One is the ghost.uunet.ca using SUN4 and my work place sietec.sni.ca using
Netblazer.  Both sites are using T3000 modems. My ISC box has T2500 modem.
I use FAS 2.08 serial line driver.

The network layout:

ghost.uunet.ca		sietec.sni.ca			modtor.mod.sni.ca
(SUN 4)			(Netblazer)			(ISC 2.2.1)
==========================================================================
eth:142.77.1.1		eth:192.75.236.242		eth:192.75.238.240
			eth:192.75.237.242

slip:142.77.254.1<----->slip:142.77.254.9
			slip:192.75.238.1<------------->slip:192.75.238.2
or

slip:142.77.254.1<------------------------------------->slip:142.77.254.9

3. In /etc/netd.cf I have the following stuff:

To link SLIP STREAM module:

>sl_ip  = "/dev/sl" lsap 0x888   # stream for IP messages
>link sl_ip under ip_tcp name "sl0"

To configure SLIP interface:
(depending on which destination I need as a default I uncomment
one of the ifconfig lines)

># For uunet.ca connection:
>#ifconfig "sl0" mod-sl1 uu-sl netmask 255.255.255.0 up
># For sni.ca connection:
>ifconfig "sl0" mod-sl0 sni-sl netmask 255.255.255.0 up

4. The ifconfigs above can be read only in the context of my /etc/hosts file:

>127.0.0.1       localhost local loghost
>192.75.238.240  modtor
>192.75.238.1    sni-sl
>192.75.238.2    mod-sl0
>142.77.254.1    uu-sl

On top of the /etc/hosts file (used only during boot time) I run the DNS
named which is very useful when connecting to large remote networks (Internet).
My home domain is mod.sni.ca.

5. Both sides of the SLIP connection must have a proper routing set up.
On each side of the connection there must be two routes present.
(The following routes describe modtor.mod.sni.ca side routes when
modtor.mod.sni.ca connecting to sietec.sni.ca).

One that is taken care of by the ifconfig (run manually or by the netd from
netd.cf) that list remote SLIP interface as destination and local SLIP interface
as a gateway. On modtor.mod.sni.ca the 'netstat -r' line listing this route is:

Routing tables
Destination          Gateway              Flags    Refcnt Use        Interface
sni-sl.mod.sni.ca    mod-sl0.mod.sni.ca   UH       0      0          sl0

The second route that has to be set up manually points to the final destination
(that might be a host address, net address or a 'default') using remote SLIP
interface as a gateway. On modtor.mod.sni.ca the netstat -r for this route is:

Routing tables
Destination          Gateway              Flags    Refcnt Use        Interface
default              sni-sl.mod.sni.ca    UG       0      0          sl0

To setup this route I have a file /etc/routes that I source from my /etc/rc
files and do it at boot time. It contains:

>route add default sni-sl 1.

I do not run gated or routed. All routes on modtor are static.

Remember boths sides of the connection must have both above equivalent routes
set up to get even ping(1) to work. On the Netblazer at sni.ca I have an
local interface with adddres 192.75.238.1 and two routes:

Destination		Gateway
192.75.238.2		192.75.238.1
192.75.238		192.75.238.2

6. To establish the SLIP session I use stock ISC sldialup.

> sldialup /dev/ttyF01 19200

Log in and put sldialup in background using <esc> key.

7.To terminate session use kill -9 on the sldialup process.

Happy slipping - peter.
-- 
Peter Ziobrzynski, peter@modtor.UUCP, peter@sni.CA
1850 Rathburn Rd. E #1611, Mississauga, Ont. L4W 2X9, Canada
tel. +1 (416) {home:625-1684, work:496-8510, fax:496-8524}
Newsgroups: comp.unix.sysv386