While DNS walking during the recon phase, Ryan discovers two hosts that should exist and have available services, but when he performs an inverse scan on them he gets confusing results. He can reach them through a web browser, confirming they have http services running, but the scan produces only RST, ACK responses. Why?
A) Ryan is inverse scanning a Windows host
B) Ryan is inverse scanning a Linux host
C) The filter is returning the RST flags to discourage the scan
D) The HTTP server always responds with a RST if the browser agent is not Mozilla or IE

Question

Quizplus · Accepted Answer

A Windows host will always respond to inverse scans with a RST whether the target port is open or closed. Ultimately, inverse scans might be helpful in determining basic filter rules or for discovery of live hosts, but will only produce meaningful port scan results if the target of the scan is a Linux host.

While DNS Walking During the Recon Phase, Ryan Discovers Two