Open In App

Host Discovery in Nmap Network Scanning

Improve
Improve
Like Article
Like
Save
Share
Report

Nmap becomes the primary tool for scanning the network, while other scanner tools still compete with Nmap. Many hosts in the organization are filtered by the firewall which is not detectable in the network.  But this can be possible using host discovery using Nmap. Host discovery in Nmap is the process of gathering information about the host in the respective network. Host discovery is also known as ping scan. Nmap uses options like ping or built-in script to look after ports, services, and running servers on respective IPs using TCP and UDP. This may lead to further enumeration.

The function of Host discovery in Nmap:

  • List Scan: A list scan generally lists the possible host without sending any packets to the targeted host.

nmap -sL www.geeksforgeeks.com

List Scanning

 

  • Ping Sweep: Ping sweep discovers on the basis the host is powered on.

nmap -sP www.geeksforgeeks.com

Ping Sweep scanning

 

  • Disable ARP Ping: Nmap mostly uses ARP ping to discover the other host in the network. To disable ARP Ping, use option –disable-arp-ping.

nmap -sn www.geeksforgeeks.com –disable-arp-ping 

Disabling ARP Ping

 

  • TCP SYN Ping: Nmap checks whether a host is online.

nmap -PS www.geeksforgeeks.com 

TCP SYN Ping

 

  • TCP ACK Ping: Nmap checks whether the host is responding.

nmap -sA www.geeksforgeeks.com

TCP SYN Ping

 

  • ICMP Echo Ping: Nmap sends ICMP packets to the available host.

nmap -PE www.geeksforgeeks.com

ICMP Echo Ping

 

  • UDP Ping: Nmap sends the UDP packets to the targeted port.

nmap  -sU www.geeksforgeeks.com

UDP Ping

 

  • IP Protocol Ping: Nmap tries to send different packets using different protocols.

nmap -v -PO www.geeksforgeeks.com

IP Protocol Ping

 

  • ARP Ping: ARP ping scan is used to discover the host devices in the same network. sometimes it will not visible due to firewall filtering.

nmap -PR www.geeksforgeeks.com

ARP Ping

 

  • Traceroute: Traceroute helps to discover the following hops or pathways to the targeted host.

nmap -sn –traceroute www.geeksforgeeks.com

Traceroute

 


Last Updated : 02 Oct, 2022
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads