2.6. Network Services

2.6.1. DHCP Server

YaST can set up a custom DHCP server in only a few steps. Chapter 21.11. “DHCP” provides basic knowledge about the subject as well as a step-by-step description of the configuration process in YaST.

2.6.2. Host Name and DNS

Use this module for configuration of host name and DNS, if these settings were not already been made while configuring the network devices.

2.6.3. NFS Client and NFS Server

NFS enables you to operate a file server that can be accessed by members of your network. On this file server, you can make programs, files, or storage space available for users. Use the NFS Server module to set up your computer as an NFS server and to determine the directories to export for use by the network users. Subsequently, any user (holding the required permissions) can mount these directories in his own file tree. The description of the YaST module and background information about NFS is provided in Section 21.10. “NFS — Shared File Systems”.

2.6.4. Configuration of a Samba Server

Set up a Samba server to share resources such as files or printers with Windows hosts. In the first dialog, define the role of the Samba server. You can deactivate it, use it as a file and print server, or use it as a backup or primary domain controller. A file and print server makes directories and printers available. A domain controller enables its clients to log in to a Windows domain. The primary domain controller manages users and passwords. A backup domain controller uses another domain controller for authenticating the users. More information about Samba is available in Section 24.1. “Samba”.

2.6.5. Configuration of Samba Clients

Configure a Samba client to access resources (files or printers) on the Samba server. In the Samba Workgroup dialog, enter the domain or workgroup. Use Browse to display all available groups and domains and select one of them with a mouse click. If you activate Also Use SMB Information for Linux Authentication, user authentication is conducted via the Samba server. After specifying all settings, click Finish to complete the configuration.

2.6.6. NTP Client

NTP (Network Time Protocol) is a protocol for synchronizing the clocks of network hosts. In the respective YaST module, select a type with Add. Several options are then displayed. Server and Radio clock are the most frequently-used options. Radio clock requires special hardware.

If you select Server, enter the address of an NTP server when prompted. You can enter one of the public NTP servers listed at http://www.eecis.udel.edu/~mills/ntp/servers.html. Confirm with OK.

To start the NTP daemon when the system is booted, select When booting system. Save your settings with Finish. More information about NTP is provided in Section 21.12. “Time Synchronization with xntp”.

2.6.7. Routing

Information about routing is provided in Section 21.5. “Routing in SUSE LINUX”.

2.6.8. Mail Transfer Agent

This module configures your mail settings if you send your e-mail with sendmail, postfix, or the SMTP server of your provider. You can fetch mail via the fetchmail program, for which you can also enter the details of the POP3 server or IMAP server of your provider.

You can also use a mail program of your choice, such as KMail or Evolution, to set your POP and SMTP access data as usual (to receive mail with POP3 and send mail with SMTP). In this case, you do not need this module. Connection Type

To configure your mail with YaST, specify the desired type of connection to the Internet in the first dialog of the e-mail configuration module. Choose one of the following options:


Select this option if you have a dedicated line to the Internet. Your machine is online permanently, so no dial-up is required. If your system is part of a local network with a central e-mail server, select this option to ensure permanent access to your e-mail messages.


This item is relevant for users who have a computer at home, are not located in a network, and occasionally connect to the Internet.

No connection

If you do not have access to the Internet and are not located in a network, you cannot send or receive e-mail.

Furthermore, you can activate virus scanning for your incoming and outgoing e-mail with AMaViS by activating the respective check box. The package is installed automatically as soon as you activate the mail filtering feature. In the following dialogs, specify the outgoing mail server (usually the SMTP server of your provider) and the parameters for incoming mail. If you use a dial-up connection, specify diverse POP or IMAP servers for mail reception by various users. By means of this dialog, you can also assign aliases, use masquerading, or set up virtual domains. Click Finish to exit the mail configuration.

2.6.9. Mail Server

[Important]LDAP-Based Mail Server Configuration

The mail server module of SUSE LINUX Enterprise Server only works if the users, groups, and the DNS and DHCP services are managed with LDAP.

The mail server module allows configuration of SUSE LINUX Enterprise Server as a mail server. YaST assists with the following steps of the configuration process:

Global Settings

Configures the identification of the local mail server as well as the maximum size of incoming or outgoing messages and the type of mail transport.

Local Delivery

Configures the type of local mail delivery.

Mail Transports

Configures special transport routes for mail depending on its target address.

SPAM Prevention

Configures the SPAM protection settings of the mail server. This activates the virus detection tool AMaViS after setting the type and strictness of the SPAM checking up to completely blocking acceptance of mail from certain hosts or clients.

Mail Server Relaying

Determines from which networks the mail server cannot be used for sending non-local mail.

Fetching Mail

Configures mail pick-up from external mail accounts over various protocols.

Mail Server Domains

This determines for which domains the mail server should be responsible. At least one master domain must be configured if the server should not run as a null client used exclusively for sending mail without receiving any.

Distinguish among three different domain types:


Main or master domain of the local mail server


All users who can receive mail in a master domain can also receive mail in a local domain. In the case of a message within the local domain, only the portion before the @ is evaluated.


Only those users with an explicit adress within a virtual domain receive mail. Virtual mail addresses are set up in the user management module of YaST.

2.6.10. Network Services (inetd)

This tool allows you to determine which network services (such as telnet, finger, talk, and ftp) should start when SUSE LINUX boots. These services enable external hosts to connect to your computer. You can also configure various parameters for each service. By default, the master service that manages the individual services (inetd or xinetd) is not started.

When this module starts, choose which of the two services to configure. The selected daemon can be started with a standard selection of network services. If desired, Add, Delete, or Edit services to compose your own selection of services.

[Warning]Configuration of Network Services (inetd)

The deployment and adjustment of network services on a system is a complex procedure that requires a complete understanding of the concept of Linux services.