This document provides an overview of common GNU/Linux server applications including Apache HTTP server, Squid proxy and cache server, Samba file sharing server, vsftpd FTP server, PostgreSQL and MySQL database servers, sendmail and postfix email servers, firewalls, and more. It describes features and basic usage of these open source server applications that can be used to deploy core network services on GNU/Linux servers.

1. GNU/Linux Servers
NFM 2008

2. Majour Servers
● Apache HTTP Server
● Squid Proxy and Cache
● Samba Server
● FTP Server [vsftpd]
● Database Server [Postgresql,Mysql,Sqllite]
● Email Server [sendmail,postfix]
● Firewall

3. Web Server
Apache

4. Introduction to Apache
● The Apache group was formed in 1995
● Apache => A Patchy Server
● Largely because the patches to NCSA server that
resulted in this new webserver. It actually got its
name from the native American Tribe
● Apache Version 1.0 was released in December, 1995
● World's most used web­server since April, 1996
● http://news.netcraft.com/archives/web_server_survey.ht
● 50.43% october 2008

5. Facts
● Easy administration using web based
interface [webmin]
● No cost to setup a server.
● As easy as download a CD and install.
● Lower maintenance.
● Keeps running for years.
● Better Security than IIS

7. Features
● Virtual Hosting
● Acess Configuration
● Security
● mod_rewrite

8. Single website/Virtual Hosting
● Single Website
● The host definitions go into the main configuration
● Any connection to the server returns the same set of page
● Virtual Hosting
● Ip based virtual hosting
– Multiple IP addresses to the same machine
● Name based virtual hosting
– Multiple domain names to the same IP address
● Port based virtual hosting
– Hanlding the request in a particular port

9. Access Configuration
● Allow from
● Allow access from the given networks and addresses or
when the environment satisfies a condition
● Deny from
● Deny access from the given networks and addresses or
when the environment satisfies a condition

10. Security
● mod_ssl
● Set SSLCertificateFile and SSLCertificateKeyFile
● Digital certificates from OpenSSL
● mod_security
● can the incoming requests for attacks and can
proactively prevent attacks on the server
● mod_userdir
● nables “~username” urls for user

11. mod_rewrite
● Rewrite Incoming Url based on regular
expressions
● Help Making Clean Urls in dynamic content
generation like php
● Can Use Regular Expressions for rewrite
● Using .htaccess in each directory

12. More ...
● mod_proxy can take care of proxy, both
reverse and forward
● Perl, Python and Ruby have script engines
that come as modules to Apache
● Apache is the most used webserver, since
1996 :)
● 59% of world wide web servers are apache

13. Proxy Server
Squid

14. Introduction to Proxy
● In a typical setup a Web­Proxy requests
pages from the Internet on behalf of the clients
on the local network and serves them to the
local clients.
– Enhances security on LAN
– When caching is enabled, gives a better browsing
experience
● Proxy servers also cache data and avoid
redundant and repeated requests to servers for
the same data.
●

15. Features of Squid
● Web Proxy and Cache for HTTP, FTP
● DNS Lookup Cache
● Reverse Proxy to accelerate speed of web
servers
● Access Control Lists
● Bandwidth management

16. Network File Sharing Server
Samba

17. Introduction to SMB
● NetBIOS by IBM and Sytec
● NetBIOS + Disk I/O redirection => SMB
– Server Message Block Protocol by Microsoft
– Now called the CIFS [Common Internet File System]
● Windows machines advertise their services
and presence on the network using this
protocol
● The “Network Neighbourhood”

18. Introduction to Samba
● Andrew Tridgell published his code in early
1992
● Actual development started two years later
● Opening windows to the wider world
● Samba runs on unix platforms, but speaks to
Windows clients like a native windows machine
● Lets you share files and printers over the
network
● Works with SMB as well as its latest form
CIFS

19. Features Samba
● File and Printer sharing
● Access controls
● Remote Logons
● Work As a part of windows Network
● Can Act as the Primary Domain Controller
● SWAT (Samba Web Administration Tool)

20. Ftp Server
Vsftpd

21. Introduction to FTP
● File Transfer Protocol
● Criticisms
– Passwords are sent in clear­text
– Multiple TCP/IP connections needed
– No integrity check in case of connection failures
● Alternatives
– SFTP and FTPS for secure copying
– Secure Copy or SCP is now­a­days largely used

22. Features of vsftpd
● A simple FTP server
● Anonymous access
● Security considerations
● Easy Configuration

23. Active Directory
Open LDAP

24. Features
● Active Directory is essentially LDAP and
Kerberos tied together (although slightly
Modified)
● OpenLDAP is the usual LDAP implementation
● If you decide to keep Active Directory, Samba
version 3.0 or higher is needed to integrate well
with it

25. Domain Name System (DNS) server
BIND
[Berkeley Internet Name Domain]

26. Features of BIND
● Berkeley Internet Name Domain (BIND) is one
of the many industry standard Open Source
packages that make up much of the Internet
infrastructure.
● Domain name serving is one of the easiest (and
most transparent to the end user) conversions
you' face.
● BIND works from plain text configuration files,
not a GUI.

27. Dynamic Host Configuration
Protocol
(DHCP) server
ISC’s DHCP

28. Features
● ISC’s DHCP is industry standard Open Source
Package
● it works better with Windows clients than a
Windows DHCP server
● DHCP server keeps its configuration data in
a .mdb file

29. Web Application Server (Java)
● Lots of products in this area. Probably the
same ones that you run on Windows are
available for Linux
– WebSphere
– BEA WebLogic
– Iplanet
– Jboss
● Installation, configuration and management
should be the same or very similar across
platforms

30. Remote Access Server
● Use the pppd package that comes with your
distribution
● pppd supports a variety of authentication
protocols, such as PAP, CHAP, and RADIUS
● IP forwarding must be turned on in the Linux
kernel
● Kpp GUI is available

31. Email Server
● lots of choices on Linux
● Sendmail,
● Exim,
● Postfix,
● The email delivery piece is the easy part

32. Groupware Server
● Bynari’s Insight server is one, but only scales
up to about 50,000 email boxes.
● Ximian Insight Connector (now owned by
Novell) is another
●

33. Database Server
● The two most popular Open Source ones are
● MySQL and PostgreSQL
● MySQL easy flexible
● PostgreSQL is strong and enterprise class.

34. Firewall
● Linux comes with a native firewall capability
● Linux also has native support for Network
Address Translation (NAT), also known as IP
masquerading
● The iptables command is what is used to create
firewall and NAT rules. There are GUI front­
ends available to make that easier.
● • Commercial firewalls are also available for
Linux, such as Check Point’s Firewall­1,
Phoenix, StoneGate, etc.

35. Thanks