LPI Linux Certification in a Nutshell, 2nd Edition

Networking Services (Topic 1.113)

Objective 1: Configure and Manage inetd, xinetd, and Related Services

• inetd is the Internet superdaemon; it listens on multiple inbound ports and launches the appropriate child daemon to service the requests.

• inetd uses TCP wrappers (tcpd) to add access security to services .

• inetd is configured in /etc/inetd.conf.

• You can eliminate an inbound service managed by inetd simply by commenting out its declaration in /etc/inetd.conf and restarting or signaling inetd.

• TCP wrappers allow the administrator to define access rules for hosts. The configuration files are /etc/hosts.allow and /etc/hosts.deny.

Objective 2: Operate and Perform Basic Configuration of Mail Transfer Agent (MTA)

• Sendmail is a Mail Transfer Agent (MTA).

• Sendmail is configured in /etc/sendmail.cf. This file is generally regarded as difficult to configure.

• The "smart host" parameter is used to configure a local Sendmail daemon to transfer mail to a site's official mail system.

• /etc/aliases is a file that stores aliases for inbound mail addresses; it can redirect mail to one or more users.

• Whenever /etc/aliases is modified, newaliases must be executed.

• Each user can forward his own mail using a .forward file, containing the forwarding email address, in his home directory.

• Outbound mail that is trapped due to a network or other problem will remain queued; it can be examined using the mailq command.

Objective 3: Operate and Perform Basic Configuration of Apache

• Apache is configured using httpd.conf ...