Copyright Goodheart-Willcox Co., Inc. 483 Chapter 15 Network Security Self-Hack Tools Several companies have self-hack tools available. Th ese tools are typically built into a security package and off ered as an additional feature. For example, GFI LANguard is not only designed to provide security measures for a network it can also test network security using common methods such as password cracking. GFI LANguard probes the LAN for open communication ports and general security weaknesses. It also pro- vides a password-cracking tool. Protocol Analyzer A protocol analyzer is a special software application used to monitor a network and inspect frame/packet contents. Protocol analyzers are sometimes referred to as protocol sniff ers. It can reveal information about protocols, such as the source and destination IP address, MAC address, port address, time of transmission, and the contents of unencrypted packets. Figure 15-27 shows an e-mail transmission. Take a close look at the contents of the e-mail, which are translated on the right side of the screen. In the translation, you will see the password and the username issued to the recipient because the e-mail was not encrypted. Th e contents of this e-mail are revealed to anyone using a proto- col analyzer or protocol sniff er on this network. Another excellent tool is the Fluke OptiView Protocol Analyzer. In fact, Fluke has an entire series of network analyzing tools to help you inspect a network system. Related to protocol analyzers are port scanners. Th ese literally scan a target to see what ports are open and listening. 5.2 NET Figure 15-27 Notice how the contents of an unencrypted e-mail can be revealed to anyone using a protocol analyzer or protocol sniffer. Look closely and you will see the password contained in the e-mail. Goodheart-Willcox Publisher Packet Sniffer A packet sniff er is a network monitoring utility that captures data packets as they travel across a network. As shown in Figure 15-28, a packet sniff er provides a vast amount of information such as packet size, protocol, and the source and destina- tion address expressed as an IP address and a MAC address. On the right side of the screen, you can see some of the information contained inside the decoded packet. Th e packet sniff er seen in Figure 15-28 can capture and perform a complete analysis of TCP, IP, ARP, and UDP protocols. Th is utility can be very useful in analyzing net- work problems. However, in the wrong hands, it can be a security threat. 5.2 NET