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NMAP port states explanation - TCP ACK -sA


ACK scan is meant to be used for mapping firewall rule sets rather than discovering listening ports on hosts.
As we can see below all combinations gave the same result.  


TCP ACK
Service State
No Firewall
Firewall
-sA
Listening

State: Unfiltered

State: Unfiltered

nmap
target
ACK
RST
nmap
target
ACK
RST
Not Listening

State: Unfiltered


State: Unfiltered
nmap
target
ACK
RST
nmap
target
ACK
RST

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