While attempting to discover the remote operating system on the target computer, you receive the following results from an nmap scan:

Starting nmap V. 3.10ALPHA9 ( www.insecure.org/nmap/

<http://www.insecure.org/nmap/> )

Interesting ports on 172.121.12.222:

(The 1592 ports scanned but not shown below are in state: filtered)

Port State Service

21/tcp open ftp

25/tcp open smtp

53/tcp closed domain

80/tcp open http

443/tcp open https

Remote operating system guess: Too many signatures match to reliably

guess the OS.

Nmap run completed — 1 IP address (1 host up) scanned in 277.483

seconds

What should be your next step to identify the OS?

Which of the following systems would not respond correctly to an nmap XMAS scan?

What ICMP message types are used by the ping command?

You are scanning into the target network for the first time. You find very few conventional ports open. When you attempt to perform traditional service identification by connecting to the open ports, it yields either unreliable or no results. You are unsure of what protocols are being used. You need to discover as many different protocols as possible. Which kind of scan would you use to do this?

Because UDP is a connectionless protocol: (Select 2)

What does an ICMP (Code 13) message normally indicates?

What port scanning method is the most reliable but also the most detectable?

What port scanning method involves sending spoofed packets to a target system and then looking for adjustments to the IPID on a zombie system?

An Nmap scan shows the following open ports, and nmap also reports that the OS guessing results to match too many signatures hence it cannot reliably be identified:

21 ftp

23 telnet

80 http

443 https

What does this suggest ?

John has scanned the web server with NMAP. However, he could not gather enough information to help him identify the operating system running on the remote host accurately.

What would you suggest to John to help identify the OS that is being used on the remote web server?