Day 11 · Week 2

nmap host discovery

Complete TryHackMe nmap host discovery

Challenges completed

Completed nmap host discovery room

What I learned

  • Refreshed knowledge around OSI layers, and what protocols, such as ARP, TCP, UDP, ICMP belongs in what layer

  • Host discoverying using:

    • ARP
    • ICMP
    • TCP and UDP
  • Reverse DNS look up

Commands, tools, and techniques

  • host discovery only: -sn
  • ARP Scan - sudo nmap -PR -sn 10.200.6.0/24
  • ICMP Echo Scan - sudo nmap -PE -sn 10.200.6.0/24
  • ICMP Timestamp Scan - sudo nmap -PP -sn 10.200.6.0/24
  • ICMP Address Mask Scan - sudo nmap -PM -sn 10.200.6.0/24
  • TCP SYN Ping Scan - sudo nmap -PS22,80,443 -sn 10.200.6.0/30
  • TCP ACK Ping Scan - sudo nmap -PA22,80,443 -sn 10.200.6.0/30
  • UDP Ping Scan - sudo nmap -PU53,161,162 -sn 10.200.6.0/30
  • no DNS look up: -n
  • reverse DNS look up: -R

Problems and dead ends

Explain what did not work and why.

What I will revisit

  • Subnets