Which security measure is best used to limit the success of a reconnaissance attack from within a campus area network?
- Implement a firewall at the edge of the network.
- Implement restrictions on the use of ICMP echo-reply messages.
- Implement encryption for sensitive traffic.
- Implement access lists on the border router.
Explanation & Hint: The implementation of an access list may provide extra security by permitting denying a flow of traffic, but it will not provide a direct response to limit the success of the attack. The implementation of a firewall on the network edge may prevent reconnaissance attacks from the Internet, but attacks within the local network are not prevented. By implementing restrictions on the sending of ICMP echo-reply messages within a local network, devices may not respond to ping messages, but port scans are not prevented and clear-text data sent on the network are still vulnerable. The best security measure is to encrypt as much network traffic as possible, both user data and network management traffic. |