• Antisniffer tools: Software and hardware designed to detect the use of sniffers on a network can be employed. Such software and hardware does not completely eliminate the threat, but like many network security tools, they are part of the overall system. These antisniffer tools detect changes in the response time of hosts to determine whether the hosts are processing more traffic than their own traffic loads would indicate. One such network security software tool called AntiSniff, is available from Security Software Technologies.

• Cryptography: Rendering packet sniffers irrelevant is the most effective method for countering packet sniffers. Cryptography is even more effective than preventing or detecting packet sniffers. If a communication channel is cryptographically secure, the only data a packet sniffer detects is cipher text (a seemingly random string of bits) and not the original message. The Cisco deployment of network-level cryptography is based on IPSec, which is a standard method for networking devices to communicate privately using IP.

- CITC - NTS Support Centre