Low-Level Protocol

Information network protocols send between computers includes hardware addresses of local network interfaces, the IP addresses of remote network interfaces, IP routing information, and sequence numbers assigned to bytes on a TCP connection. Knowledge of any of this information can be misused by someone interested in attacking the security of machines on the network. See the second part of this chapter for more information on how these data can pose risks for the security of a network. A sniffer can obtain any of these data. After an attacker has this kind of information, he or she is in a position to turn a passive attack into an active attack with even greater potential for damage.