⇒ nmap -Pn -T{0,1,2,3,4} 8.8.8.8

• The -Pn option in Nmap is used to skip host discovery and treat all specified target hosts as online.

⇒ Scan Type [ SYN or Connect or UDP ]

nmap -s{ S | T | U }

-sS : SYN Scan

-sT : Connect [ SYN , SYN ACK , ACK ]

⇒ Scan Specific Port

• nmap -p { 21,22,80,443}
• nmap - -top-ports 100

To Store Results in file nmap -oA filename

Special Options

nmap - - reason

nmap -p 21,22,5555 10.0.2.10 --reason Reason here gives you why the port is opened or closed