What can you infer from this observation?

While scanning a network you observe that all of the web servers in the DMZ are responding to ACK packets on port 80.

What can you infer from this observation?
A . They are using Windows based web servers.
B . They are using UNIX based web servers.
C . They are not using an intrusion detection system.
D . They are not using a stateful inspection firewall.

View Answer

Answer: D

Explanation:

If they used a stateful inspection firewall this firewall would know if there has been a SYN-ACK before the ACK.