Translations by Tomasz Dominikowski

ubuntu-doc@lists.ubuntu.com (Ubuntu Documentation Project)

bhuvan@ubuntu.com (Bhuvaneswaran Arumugam)

robbieboy@gmail.com (Robert Stoffers)

bshumate@openmindshare.com (Brian Shumate)

Ubuntu Server Guide

2006-04-06

An introduction to installing and configuring server applications on Ubuntu.

Windows Networking

Introduction

Successfully networking your Ubuntu system with Windows clients involves providing and integrating with services common to Windows environments. Such services assist the sharing of data and information about the computers and users involved in the network, and may be classified under three major categories of functionality:

<emphasis role="bold">File and Printer Sharing Services</emphasis>. Using the Server Message Block (SMB) protocol to facilitate the sharing of files, folders, volumes, and the sharing of printers throughout the network.

<emphasis role="bold">Directory Services</emphasis>. Sharing vital information about the computers and users of the network with such technologies as the Lightweight Directory Access Protocol (LDAP) and Microsoft <trademark class="registered">Active Directory</trademark>.

<emphasis role="bold">Authentication and Access</emphasis>. Establishing the identity of a computer or user of the network and determining the information the computer or user is authorized to access using such principles and technologies as file permissions, group policies, and the Kerberos authentication service.

Fortunately, your Ubuntu system may provide all such facilities to Windows clients and share network resources among them. One of the principle pieces of software your Ubuntu system includes for Windows networking is the SAMBA suite of SMB server applications and tools. This section of the <phrase>Ubuntu</phrase> Server Guide will briefly introduce the installation and limited configuration of the SAMBA suite of server applications and utilities. Additional, detailed documentation and information on SAMBA is beyond the scope of this documentation, but exists on the <ulink url="http://www.samba.org">SAMBA website</ulink>.

Installing SAMBA

At the prompt enter the following command to install the SAMBA server applications:

Configuring SAMBA

You may configure the SAMBA server by editing the <filename>/etc/samba/smb.conf</filename> file to change the default settings or add new settings. More information about each setting is available in the comments of the <filename>/etc/samba/smb.conf</filename> file or by viewing the <filename>/etc/samba/smb.conf</filename> manual page from the prompt with the following command typed at a terminal prompt:

man smb.conf

Prior to editing the configuration file, you should make a copy of the original file and protect it from writing so you will have the original settings as a reference and to re-use as necessary.

Backup the <filename>/etc/samba/smb.conf</filename> file:

sudo cp /etc/samba/smb.conf /etc/samba/smb.conf.original

Now, edit the <filename>/etc/samba/smb.conf</filename> file and make your changes.

Server

In addition to the SAMBA suite of file and printer sharing server applications, Ubuntu also includes other powerful server applications designed to provide additional network server functionality to Windows clients similar to the functionality provided by actual Windows servers. For example, Ubuntu offers centralized management of network resources such as computers and users via Directory Services, and facilitates the identification, and authorization of computers and users via Authentication Services.

The following sections will discuss SAMBA and the supporting technologies, such as Lightweight Directory Access Protocol (LDAP) server, and Kerberos authentication server in more detail. You will also learn about some of the available configuration directives available the SAMBA configuration file which facilitate network integration with Windows clients and servers.

Active Directory

Active Directory is a proprietary implementation of Directory Services by Microsoft, and is used to provide a means to share information about network resources and users. In addition to providing a centralized source of such information, Active Directory also acts as a centralized authentication security authority for the network. Active directory combines capabilities traditionally found in separate, specialized directory systems to simplify integration, management, and security of network resources. The SAMBA package may be configured to use Active Directory services from a Windows Domain Controller.

LDAP

The LDAP server application provides Directory Services functionality to Windows computers in a manner very similar to Microsoft Active Directory services. Such services include managing the identities and relationships of computers, users, and groups of computers or users that participate in the network, and providing a consistent means to describe, locate, and manage these resources. The freely available implementation of LDAP available for your Ubuntu system is called <emphasis role="italic">OpenLDAP</emphasis>. The server daemons responsible for handling OpenLDAP directory requests and the propagation of directory data from one LDAP server to another on Ubuntu, are <application>slapd</application> and <application>slurpd</application>. OpenLDAP may be used in conjunction with SAMBA to provide File, Print, and Directory services in much the same way a Windows Domain Controller does so long as SAMBA is compiled with LDAP support.

Kerberos

realm = DOMAIN_NAME

security = ADS

to the file, and save the file.

Be sure to replace the token DOMAIN_NAME in the example above with the actual name of your specific Windows Domain.

You will need to restart the SAMBA daemons to effect these changes. Restart the SAMBA daemons with the following command entered at a terminal prompt:

sudo /etc/init.d/samba restart

Computer Accounts

Computer Accounts are used in Directory Services to uniquely identify computer systems participating in a network, and are even treated in the same manner as users in terms of security. Computer accounts may have passwords just as user accounts do, and are subject to authorization to network resources in the same manner as user accounts. For example, if a network user, with a valid account for a particular network attempts to authenticate with a network resource from a computer which does not have a valid computer account, depending upon policies enforced on the network, the user may be denied access to the resource if the computer the user is attempting authentication from is considered to be an unauthorized computer.

A computer account may be added to the SAMBA password file, provided the name of the computer being added exists as a valid user account in the local password database first. The syntax for adding a computer or machine account to the SAMBA password file is to use the <application>smbpasswd</application> command from a terminal prompt as follows:

sudo smbpasswd -a -m COMPUTER_NAME

Be sure to replace the token COMPUTER_NAME in the example above with the actual name of the specific computer you wish to add a machine account for.

File Permissions

File Permissions define the explicit rights a computer or user has to a particular directory, file, or set of files. Such permissions may be defined by editing the <filename>/etc/samba/smb.conf</filename> file and specifying the explicit permissions of a defined file share. For example, if you have defined a SAMBA share called <emphasis role="italic">sourcedocs</emphasis> and wish to give <emphasis role="italic">read-only</emphasis> permissions to the group of users known as <emphasis role="italic">planning</emphasis>, but wanted to allow writing to the share by the group called <emphasis role="italic">authors</emphasis> and the user named <emphasis role="italic">richard</emphasis>, then you could edit the <filename>/etc/samba/smb.conf</filename> file, and add the following entries under the <emphasis role="italic">[sourcedocs]</emphasis> entry:

read list = @planning

write list = @authors, richard

Save the <filename>/etc/samba/smb.conf</filename> for the changes to take effect.