TuxTraining

nmap -sP 10.50.100.1-255
Starting nmap 3.70 ( http://www.insecure.org/nmap/ ) at 2008-10-07 15:50 PDT
Host 10.50.100.1 appears to be up.
Host 10.50.100.2 appears to be up.
Host 10.50.100.22 appears to be up.
Host mondo (10.50.100.72) appears to be up.
Host 10.50.100.82 appears to be up.
Nmap run completed -- 255 IP addresses (5 hosts up) scanned in 3.228 seconds

# nmap -v -sP 192.168.1.0/24

You can replace the 192.168.1.0/24 address with whatever your IP and subnet is.

Also, for a cleaner output that removes the lines that tell you an IP is not used, try the following:

# nmap -v -sP 192.168.1.0/24 | grep -v "appears to be down"

Remote OS Fingerprinting is becoming more and more important, not only for security pen-testers,but for the black-hat. Just because Nmap is getting popularity as the tool for guessing which OS is running in a remote system, some security tools have been developed to fake Nmap in its OS Fingerprinting purpose. This document describes a solution to defeat Nmap and behave like another chosen operating system, as well as a demonstration on how can be accomplished.

(more…)

nmap has -D option. It is called decoy scan. With -D option it appear to the remote host that the host(s) you specify as decoys are scanning the target network too. Thus their IDS might report 5-10 port scans from unique IP addresses, but they won’t know which IP was scanning them and which were innocent decoys. While this can be defeated through router path tracing, response-dropping, and other active mechanisms, it is generally an effective technique for hiding your IP address.

(more…)

Nmap is a very powerful tool with LOTS of options and features to visualize your network. Check which services are running on various hosts and find suspicious malicious programs running in your network. Even though Nmap is the swiss-army knife for network scanning, most of its benefits can be gained by the average Network Administrator without diving deep in to its complications. Chances are, most of the time you will find yourself using common switches even if you know all of them.

(more…)