Created: 2022-07-02
Tags: #fleeting
Abstract:
Nmap will connect to each port of the target in turn.
Depending on how the port responds, it can be determined as being open, closed, or filtered by a firewall.
Once we know which ports are open, we can then look at enumerating which services are running on each port.
Three basic scan types in NMAP
Additionally there are several less common port scan types.
-sN)-sF)-sX)Most of these (with the exception of UDP scans) are used for very similar purposes, however, the way that they work differs between each scan.
This means that, whilst one of the first three scans are likely to be your go-to in most situations, it's worth bearing in mind that other scan types exist.
This single reason above.
Make the defaults run by Nmap
Default Scan: SYN scans
Default Scan: TCP Connect scan.
How TCP Connect identifies if port is CLOSED/OPEN or behind firewall
How Nmap SYN Scan determines if a port is open, closed or behind firewall
How Nmap UDP Scan determines if a port is open or closed
More common port scan types
Stealth Scans
NULL
FIN
XMAS