Turn on OS and version detection scanning script (IPv4)
nmap -A 192.168.1.254
nmap -v -A 192.168.1.1
nmap -A -iL /tmp/scanlist.txt
Find out if a host/network is protected by a firewall
nmap -sA 192.168.1.254
Scan a host when protected by the firewall
nmap -PN 192.168.1.1
Scan a network and find out which servers and devices are up and running
This is known as host discovery or ping scan:
nmap -sP 192.168.1.0/24
Host 192.168.1.1 is up (0.00035s latency).
MAC Address: BC:AE:C5:C3:16:93 (Unknown)
Host 192.168.1.2 is up (0.0038s latency).
MAC Address: 74:44:01:40:57:FB (Unknown)
Host 192.168.1.5 is up.
Host nas03 (192.168.1.12) is up (0.0091s latency).
MAC Address: 00:11:32:11:15:FC (Synology Incorporated)
Nmap done: 256 IP addresses (4 hosts up) scanned in 2.80 second
Only show open (or possibly open) ports
nmap --open 192.168.1.1
Show all packets sent and received
nmap --packet-trace 192.168.1.1
Scan a host using TCP ACK (PA) and TCP Syn (PS) ping
If firewall is blocking standard ICMP pings, try the following host discovery methods:
nmap -PS 192.168.1.1
nmap -PS 80,21,443 192.168.1.1
nmap -PA 192.168.1.1
nmap -PA 80,21,200-512 192.168.1.1
How do I detect remote operating system?
You can identify a remote host apps and OS using the -O option:
nmap -O 192.168.1.1
nmap -O --osscan-guess 192.168.1.1
nmap -v -O --osscan-guess 192.168.1.1