2.7. Network Services

This group contains tools to configure all kinds of services in the network. These include name resolution, user authentication, and file services.

2.7.1. Mail Transfer Agent

You can configure your mail settings in Network Services+Mail Transfer Agent 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 or IMAP server of your provider. Alternatively, use a mail program of your choice, such as KMail or Evolution, to set your access data. In this case, you do not need this module.

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

Permanent

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.

Dial-Up

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.

Activate virus scanning for your incoming and outgoing e-mail with AMaViS by selecting that option. 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. Set the diverse POP or IMAP servers for mail reception by various users. Using this dialog, you can also assign aliases, use masquerading, or set up virtual domains. Click Finish to exit the mail configuration.

2.7.2. Other Available Services

Many other network modules are available in YaST Network Services.

DHCP Server

Use this to set up a custom DHCP server in only a few steps. Chapter 23, DHCP (↑Reference) provides basic knowledge about the subject and a step-by-step description of the configuration process.

DNS Server

Configuring a DNS server that is responsible for name resolution is recommended for larger networks. You can use DNS Server for this as described in Section 20.2, “Configuration with YaST” (↑Reference). Chapter 20, The Domain Name System (↑Reference) provides background information about DNS.

DNS and Hostname

Use this module to configure the hostname and DNS if these settings were not already made while configuring the network devices. Also use it to change the hostname and domain name. If the provider has been configured correctly for DSL, modem, or ISDN access, the list of name servers contains the entries that were extracted automatically from the provider data. If you are located in a local network, you might receive your hostname via DHCP, in which case you should not modify the name.

HTTP Server

To run your own Web server, configure Apache in HTTP Server. Find more information in Chapter 26, The Apache HTTP Server (↑Reference).

Hostnames

When booting and in small networks, you can use Hostnames for hostname resolution instead of DNS. The entries in this module reflect the data of the file /etc/hosts. For more information, read Section 18.6.1.6, “ /etc/hosts (↑Reference).

Kerberos Client

If you have a Kerberos server in your network for network authentication, use Kerberos Client.

LDAP Client

If using LDAP for user authentication in the network, configure the client in LDAP Client. Information about LDAP and a detailed description of the client configuration with YaST are available in Section 25.5, “The YaST LDAP Client” (↑Reference).

NFS Client

With NFS client, mount directories provided by NFS server in your own file trees. Use NFS Client to configure your system to access an NFS server in the network. A description of the YaST module and background information about NFS are provided in Chapter 22, Sharing File Systems with NFS (↑Reference).

NFS Server

With NFS, run a file server that all members of your network can access. This file server can be used to make certain applications, files, and storage space available to users. In NFS Server, you can configure your host as an NFS server and determine the directories to export for general use by the network users. All users with the appropriate permissions can mount these directories in their own file trees. A description of the YaST module and background information about NFS are provided in Chapter 22, Sharing File Systems with NFS (↑Reference).

NIS Client

If you run NIS server to administer user data on a central place and distribute it to the clients, configure the client here. Detailed information about NIS client and configuration with YaST is available in Section 21.2, “Configuring NIS Clients” (↑Reference).

NIS Server

If you run more than one system, local user administration (using the files /etc/passwd and /etc/shadow) is impractical and requires a lot of maintenance. In this case, administer user data on a central server and distribute it to the clients from there. NIS is one option for this. Detailed information about NIS and its configuration with YaST is available in Section 21.1.1, “Configuring a NIS Master Server” (↑Reference).

NTP Client

NTP (network time protocol) is a protocol for synchronizing hardware clocks over a network. Information about NTP and instructions for configuring it with YaST are available in Chapter 24, Time Synchronization with NTP (↑Reference).

Network Services (xinetd)

Configure the network services (such as finger, talk, and ftp) to start when SUSE Linux boots using Network Services. These services enable external hosts to connect to your computer. Various parameters can be configured for every service. By default, the master service that manages the individual services (inetd or xinetd) is not started.

When this module starts, choose whether to start inetd or xinetd. The selected daemon can be started with a standard selection of services. Alternatively, compose your own selection of services with Add, Delete, and Edit.

[Warning]Configuring Network Services (xinetd)

The composition and adjustment of network services on a system is a complex procedure that requires a comprehensive understanding of the concept of Linux services. The default settings are usually sufficient.

Proxy

Configure Internet proxy client settings in Proxy. Click Enable Proxy then enter the desired proxy settings. You can test these settings by clicking Test Proxy Settings. A small window informs you whether your proxy settings work correctly. After your settings have been entered and tested, save them by clicking Accept.

Remote Administration

To administer your machine remotely from another machine, use Remote Administration. To maintain your system remotely, use a VNC client, such as krdc, or a Java-enabled browser. Although remote administration using VNC is simple and fast, it is less secure than using SSH, so you should always keep this in mind when using a VNC server. Find detailed information about installing with a VNC client in Section 1.1.1, “Simple Remote Installation via VNC—Static Network Configuration” (↑Reference).

Allow remote administration by selecting Allow Remote Administration in Remote Administration Settings. Selecting Do Not Allow Remote Administration disables this function. Click Open Port in Firewall to allow access to your computer. Clicking Firewall Details displays network interfaces with open ports in the firewall. Select the desired interface and click OK to return to the main dialog. Click Accept to complete the configuration.

The YaST Remote Administration module is highly recommended for configuring VNC on your machine. Although the SaX2 interface also allows you to set remote access properties, it is not a substitute for YaST. It only enables you to configure your X server as a host for VNC sessions. For more information, refer to Section 2.13.6, “Remote Access Properties”.

Routing

Use Routing to configure the paths data takes over the network. In most cases, only enter the IP address of the system through which to send all data in Default Gateway. To create more complicated configurations, use Expert Configuration.

Samba Server

In a heterogeneous network consisting of Linux and Windows hosts, Samba controls the communication between the two worlds. Information about Samba and the configuration of servers is provided in Chapter 28, Samba (↑Reference).

Windows Domain Membership

In a heterogeneous network consisting of Linux and Windows hosts, Samba controls the communication between the two worlds. With the Samba Client module, you can configure your computer as member of a Windows domain. Find information about Samba and the configuration of clients in Chapter 28, Samba (↑Reference).