Nmap basics
Maniac
Nmap Basics - Overview
What is nmap?
Nmap, short for "network mapper", is an open source utility
which can quickly scan broad ranges of devices and provide
valuable information about the devices on your network. It
can be used for IT auditing and asset discovery as well as for
security profiling of the network.
Nmap Basics - Overview
What does nmap do?
Nmap uses raw IP packets to determine what hosts are
available on the network, the services that are enabled, the
operating system and version of the host, what sort of firewall
or packet filters are in place and many other aspects of the
network. The information can be used both proactively to
identify and correct security holes and by attackers to perform
reconnaissance about the types and quantities of targets
available and what weaknesses exist.
Nmap Basics - Overview
Nmap runs on?
Nmap is available for a wide range of operating system
platforms. The standard download is a compressed file
containing the UNIX version (which runs on Linux, Solaris,
Free/Net/OpenBSD, and Mac OS X) and the Windows version
as well as NmapFE, the X-Windows front end for UNIX, and
NmapWIN, the recommended Windows GUI for Nmap.
Nmap Basics - Overview
Nmap can perform a wide range of scans. Some are more
aggressive and blatant, while some are designed to be stealthy
and scan undetected. Depending on the type of scan performed,
different information can be discovered as well.
Nmap Basics - Overview
Some of the scan types are:
Connect SYN Stealth
FIN, Xmas, Null Ping
UDP Scan IP Protocol Scan
ACK Scan Window Scan
RPC Scan List Scan
FTP Bounce
Nmap Basics - First Scan
How hard is nmap to use?
Nmap’s ability to be run from both the command line and
from a GUI enable most people to get the tool up and
running very quickly. Advanced features require more
command line and technical expertise to use the tool
effectively.
Nmap Basics - First Scan
Windows users take heed:
Windows XP Service Pack 2 is shoddily supported due to the
fact that Microsoft removed the socket layer from the
Operating System. Furthermore, hacks and workarounds
that have been discovered to get nmap to work results in
Microsoft patching up this hole shortly thereafter. With this
in note, your mileage may vary.
Nmap Basics - First Scan
Basic nmap scan example.
Nmap Basics - First Scan
Application
IP Addresses scanned
Time and date of the scan
Ports discovered
State of the port
The type of service this port typically is
Total number of IP Addresses scanned
IP addresses found to be active
Number of seconds to complete the scan
Nmap Basics - Version Detection
What is host detection?
Host detection is a feature of nmap that tells it to further
analyze what the packet behavior is, and assess what
Operating System the target host is based on it’s analysis.
Ok, well what about version detection then?
Version detection expands on host detection by also querying
the ports nmap finds open for what the service is.
Nmap Basics - Version Detection
Example output from the version detection flag.
Service Info
Service Version
Unknown
Fingerprint
Unknown Service
Identifier
Nmap Basics - Version Detection
Example of host detection.
Operating System
Information
Nmap Basics - Pinging
How does nmap identify hosts?
Nmap by default will perform either a TCP SYN or a TCP
Connect ping to gather active hosts. In some cases nmap will
even use ARP pinging to identify hosts as well.
How can you turn off pinging?
The -P0 (P<zero>) switch will turn this feature off.
Nmap Basics
This concludes “Hacking With Nmap, Part 1”
Nmap Basics
Information Gathered from:
Insecurity.org - The home of Nmap
Netsecurity.about.com - Providers of the much of the Overview material.

Nmap basics-1198948509608024-3

  • 1.
  • 2.
    Nmap Basics -Overview What is nmap? Nmap, short for "network mapper", is an open source utility which can quickly scan broad ranges of devices and provide valuable information about the devices on your network. It can be used for IT auditing and asset discovery as well as for security profiling of the network.
  • 3.
    Nmap Basics -Overview What does nmap do? Nmap uses raw IP packets to determine what hosts are available on the network, the services that are enabled, the operating system and version of the host, what sort of firewall or packet filters are in place and many other aspects of the network. The information can be used both proactively to identify and correct security holes and by attackers to perform reconnaissance about the types and quantities of targets available and what weaknesses exist.
  • 4.
    Nmap Basics -Overview Nmap runs on? Nmap is available for a wide range of operating system platforms. The standard download is a compressed file containing the UNIX version (which runs on Linux, Solaris, Free/Net/OpenBSD, and Mac OS X) and the Windows version as well as NmapFE, the X-Windows front end for UNIX, and NmapWIN, the recommended Windows GUI for Nmap.
  • 5.
    Nmap Basics -Overview Nmap can perform a wide range of scans. Some are more aggressive and blatant, while some are designed to be stealthy and scan undetected. Depending on the type of scan performed, different information can be discovered as well.
  • 6.
    Nmap Basics -Overview Some of the scan types are: Connect SYN Stealth FIN, Xmas, Null Ping UDP Scan IP Protocol Scan ACK Scan Window Scan RPC Scan List Scan FTP Bounce
  • 7.
    Nmap Basics -First Scan How hard is nmap to use? Nmap’s ability to be run from both the command line and from a GUI enable most people to get the tool up and running very quickly. Advanced features require more command line and technical expertise to use the tool effectively.
  • 8.
    Nmap Basics -First Scan Windows users take heed: Windows XP Service Pack 2 is shoddily supported due to the fact that Microsoft removed the socket layer from the Operating System. Furthermore, hacks and workarounds that have been discovered to get nmap to work results in Microsoft patching up this hole shortly thereafter. With this in note, your mileage may vary.
  • 9.
    Nmap Basics -First Scan Basic nmap scan example.
  • 10.
    Nmap Basics -First Scan Application IP Addresses scanned Time and date of the scan Ports discovered State of the port The type of service this port typically is Total number of IP Addresses scanned IP addresses found to be active Number of seconds to complete the scan
  • 11.
    Nmap Basics -Version Detection What is host detection? Host detection is a feature of nmap that tells it to further analyze what the packet behavior is, and assess what Operating System the target host is based on it’s analysis. Ok, well what about version detection then? Version detection expands on host detection by also querying the ports nmap finds open for what the service is.
  • 12.
    Nmap Basics -Version Detection Example output from the version detection flag. Service Info Service Version Unknown Fingerprint Unknown Service Identifier
  • 13.
    Nmap Basics -Version Detection Example of host detection. Operating System Information
  • 14.
    Nmap Basics -Pinging How does nmap identify hosts? Nmap by default will perform either a TCP SYN or a TCP Connect ping to gather active hosts. In some cases nmap will even use ARP pinging to identify hosts as well. How can you turn off pinging? The -P0 (P<zero>) switch will turn this feature off.
  • 15.
    Nmap Basics This concludes“Hacking With Nmap, Part 1”
  • 16.
    Nmap Basics Information Gatheredfrom: Insecurity.org - The home of Nmap Netsecurity.about.com - Providers of the much of the Overview material.