Jessica works as systems administrator for a large electronics firm. She wants to scan her network quickly to detect live hosts by using ICMP ECHO Requests. What type of scan is Jessica going to perform?

An ICMP ping sweep is a fundamental network reconnaissance technique used to determine which hosts in a given IP address range are active or "live." The process involves sending a series of ICMP ECHO Request packets to every host in the target range. Systems that are online and not firewalled against this traffic will respond with an ICMP ECHO Reply message. By collecting these replies, an administrator like Jessica can quickly create a map of active devices on the network, making it an efficient method for initial host discovery.

A. Tracert: This tool is used to map the network route (the sequence of routers) to a specific destination, not to discover multiple live hosts across a network range.
B. Smurf scan: This is a type of Distributed Denial-of-Service (DDoS) attack that exploits ICMP, not a legitimate network discovery technique.
C. Ping trace: This is not a standard or recognized industry term for a network scanning method; its meaning is ambiguous.

1. Official Vendor Documentation: Fyodor. (2023). Nmap Reference Guide, Chapter 15. Nmap.org. In the "Host Discovery" section, the guide details the use of ICMP probes for discovering live hosts. Specifically, the -PE option forces an ICMP ECHO Request "ping sweep." Retrieved from https://nmap.org/book/man-host-discovery.html

2. University Courseware: Paxson, V., & Weaver, N. (2019). CS 161: Computer Security, Lecture 12: Network Security. University of California, Berkeley. Slide 21, "Scanning," explicitly describes "Ping Sweeps" as sending ICMP ECHO requests to a range of IP addresses to see who responds, identifying it as a primary method for host discovery.

3. Peer-reviewed Academic Publication: Postel, J. (1981). RFC 792: Internet Control Message Protocol. IETF. Section "Echo or Echo Reply Message" (page 14) defines the ICMP Type 8 (Echo) and Type 0 (Echo Reply) messages, which are the foundational protocol mechanisms used in an ICMP ping sweep to determine host reachability. DOI: https://doi.org/10.17487/RFC0792