Kaynak makinanın hedef makinaya TCP ACK bayraklı paket göndereceği bu tarama türünde, hedef makina tarafından ICMP Destination Unreachable mesajı dönerse yada herhangi bir tepki oluşmazsa port “filtered” olarak kabul edilir.
Eğer hedef makina RST bayraklı paket döndürürse port “unfiltered” kabul edilir :
Bu taramayı gerçekleştirmek için aşağıdaki komut kullanılmalıdır :
nmap -sA -v [Hedef_IP]
nmap -sA -v 192.168.1.2 -p80
at 2010-08-01 18:51 EEST
Initiating ARP Ping Scan at 18:51
Scanning 192.168.1.2 [1 port]
Completed ARP Ping Scan at 18:51, 0.02s elapsed (1 total hosts)
Initiating Parallel DNS resolution of 1 host. at 18:51
Completed Parallel DNS resolution of 1 host. at 18:51, 0.02s elapsed
Initiating ACK Scan at 18:51
Scanning 192.168.1.2 [1 port]
Completed ACK Scan at 18:51, 0.03s elapsed (1 total ports)
Nmap scan report for 192.168.1.2
Host is up (0.0014s latency).
PORT STATE SERVICE
80/tcp unfiltered http
MAC Address: 00:0C:29:D7:D3:65 (VMware)
Read data files from: /usr/local/share/nmap
Nmap done: 1 IP address (1 host up) scanned in 0.21 seconds
Raw packets sent: 2 (68B) | Rcvd: 2 (68B)