nmap

ex-1_iptables.adoc

@@ -101,15 +101,69 @@ See https://en.wikipedia.org/wiki/Nmap
 
 
 
-== Find open Ports
+== Scan Ports
 
 .Step 3 (find open ports)
+=== Scan a Single Port, All Ports, or Series
+
+[source,bash]
+----
+Nmap commands can be used to scan a single port or a series of ports:
+----
+
+=== Scan port 80 on the target system:
+
+[source,bash]
+----
+nmap –p 80 172.21.0.3
+----
+
+=== Scan ports 1 through 200 on the target system:
+
+[source,bash]
+----
+nmap –p 1-200 172.21.0.3
+----
+
+=== Scan (Fast) the most common ports:
+
+[source,bash]
+----
+nmap –F 172.21.0.3
+----
+
+=== To scan all ports (1 – 65535):
+
+[source,bash]
+----
+nmap –p– 172.21.0.3
+----
+
+
+
+=== Scan All TCP UDP Ports
+
+Scan all UDP and TCP ports in a single command. We will use -sU for UDP and sT for TCP protocol.
 [source,bash]
 ----
-nmap -sP 83.212.114.*
+nmap -sU -sT -p0-65535 IP
 ----
 
 
+.What Are Ports?
+[NOTE]
+====
+
+On modern operating systems, ports are numbered addresses for network traffic. Different kinds of services use different ports by default.
+
+For example, normal web traffic uses Port 80, while POP3 email uses Port 110. One of the ways that a firewall works is by allowing or restricting traffic over a particular port.
+
+Because the ports into your computer can cause a security risk, it’s critical to know which ports are open and which are blocked.
+
+====
+
+
+