RCHE Red Hat Certified Engineer Linux Study Guide[c] Exam (Rh302)

Here are some of the key points from the certification objectives in Chapter 7.

Apache

• Red Hat Enterprise Linux 3 includes the Apache Web server, which is currently used by over twice as many Internet Web sites as all other Web servers combined.

• Web services are an easy way to provide simple, secure access to many types of documents. The Apache Web server provides both normal and secure Web services using the HTTP and HTTPS protocols.

• With Apache 2.0, you can configure multiple Web sites on your server, even if you have only one IP address. This is possible through the use of virtual hosts.

Easy Squid Configuration

• Squid is a high-performance HTTP and FTP caching proxy server.

• The main Squid configuration file is long, but all you need to do in /etc/squid/squid.conf is configure the following parameters: visible_hostname, http_access, and acl.

• Squid can refer requests to sibling and parent proxy servers. If the request still isn't available, a parent proxy server refers the request to the Internet.

• Once Squid is configured, you can set each computer on the LAN to browse Web pages to the proxy server on port 3128.

The Very Secure FTP Service

• The FTP, or File Transfer Protocol, service includes a client and a server. RHEL 3 includes the command line ftp and lftp clients.

• RHEL 3 includes the vsFTP server. The default configuration allows anonymous and real user access.

• You can customize vsFTP through the /etc/vsftpd/vsftpd.conf configuration file. It also uses authentication files in the /etc directory: vsftpd.ftpusers, vsftpd.user_list, and vsftpd.chroot_list.

Mail Services

• RHEL 3 includes sendmail and postfix, two mail servers that you can use to support sending and receiving e-mail.

• The main sendmail configuration file is /etc/mail/sendmail.cf. It's easier to configure sendmail through its macro file, /etc/mail/sendmail.mc.

• You can customize the computers allowed to access your sendmail server through the access and virtusertable files in the /etc/mail directory.

• The postfix server is easier to configure through configuration files in the /etc/postfix directory. In fact, you can configure the main.cf file directly.

• Different mail clients can receive e-mail using the POP or IMAP protocols. Mail clients such as mail and mutt are available at the command line. GUI mail clients are also available, usually as part of a Web browser package.