Introduction

Introduction

We are using SuSE Linux 7.2 to setup a server for a small office solution. The main aspect of the solution is to integrate Win clients connected to our server by ethernet (LAN) and ISDN (home office). LAN only covers a single subnet (192.168.0.x). ISDN dialin only requires single user access as only one person will use this connection

network overview

In the following we refer to the linux server ibw10 on which this document is focused as “our server” in contrast to all other servers that may be participating (which are not our servers).

Requirements for our server are:

ISDN connection for dialin and dialout.
Dialout must happen on demand (whenever an IP datagram for internet is initiated).
IP masquerading must happen for Win clients. Their internet access is routed over our server and thus transparent for the user.
Server provides sendmail to transport mails originated from clients to ISP.
Server fetches emails from the ISP by fetchmail.
Server provides IMAP to present received emails to clients.
Server provides Samba to work as a fileserver for Win users.
Server provides name service (only forwarding and caching).

To setup our server you have to be user root (superuser). Most of the following commands and actions only work for user root. Some of the basic configuration like adding a user to a linux system are not covered by this document.

Our server’s hostname is ibw10 with IP address 192.168.0.10. Our local domain is domain1. Inside our local domain are all machines with IP prefix 192.168.0. Please take this in mind whenever you encounter these names in the following text. Both values are queried while installing. Check /etc/hosts and /etc/resolv.conf for those values.

Installation

The boot manager LILO did not work from start. Further investigation proved that the file /etc/lilo.conf has been created incorrectly. We have an IDE and SCSI hard disk installed. The SCSI hard disk is the boot disk and has been assigned BIOS number 0x81 which is incorrect. The right setting looks like (extract from /etc/lilo.conf):

disk    = /dev/sda
bios    = 0x80
boot    = /dev/sda

We have encountered a few problems with network card Fa311 from Netgear which were related to physical connection and not a software problem. YAST2 correctly assigned kernel module natsemi (you can query loaded modules by command /sbin/lsmod). We had suspected the interrupt assignment which can be read out by cat /proc/interrupts. But as written before the physical connection was faulty.