Data CommunicationPart 11

INTERNETINFORMATION SERVICES (IIS)

◎ IIS enables you to set a maximum connection limit on your Web server based on available bandwidth and memory.

◎ This enables you to protect your network against an overwhelming number of requests due to a particularly popular page or a type of malicious attack called a denial of service(DoS) attack.

APACHE◎ UNIX/Linux-based operating systems runApache HTTP

Server.

◎ Apache serves well over 50 percent of the Web sites on the Internet. Apache is incredibly popular, runs on multiple operating systems

◎ (including Windows), and, best of all, is free!

◎ Apache is nothing more than an executable program and a bunch of text files, so it isn’t much to look at.

◎ To ease configuration, most Web administrators use add-on graphical user interfaces (GUIs) such as Webmin that make administering Apache a breeze

WEBMIN

WEB CLIENTS

◎ programs used to surf the Web.

◎ A client program (a Web browser) reads Web pages supplied by the Web server. r

◎ Web browsers are Microsoft Internet Explorer, Mozilla Firefox, Apple, Safari, Opera, and Google Chrome.

SECURE SOCKETS LAYER AND HTTPS

◎ HTTP is not a secure protocol

◎ SSL - Secure Sockets Layer (SSL) .

◎ SSL is a protocol developed by Netscape for transmitting private documents over the Internet.

◎ SSL works by using a public key to encrypt sensitive data. This encrypted data is sent over an SSL connection, and then decrypted at the receiving end using a private

◎ key. All the popular Web browsers and Web servers support SSL, and many Web sites use the protocol to obtain confidential user information, such as credit card numbers.

◎ HTTPS stands for Hypertext Transfer Protocol over SSL.

◎ HTTPS uses TCP port 443.

TELNET

◎ Operating systems didn’t have windows and pretty icons.

◎ The interface to the mainframe was a command line

◎ Connect remotely to another computer via the command line

◎ Telnet is rarely used on the Internet and has been replaced with Secure Shell (SSH) , a terminal emulation program that looks exactly like Telnet but encrypts the data.

TELNET SERVERS AND CLIENTS

◎ The oldest Telnet server, found on UNIX and Linux systems, is the venerable telnetd.

◎ A Telnet client is the computer from which you log onto the remote

◎ server. Most operating systems have a built-in Telnet client that you run on a command prompt.