I didn't get what ports does Nmap scan. Does Nmap start from zero or one when scan subnet or all the ports?

• 0/24 is it 0-255 or is it 1-255
• -p is it 0-65535 or is it 1-65535

2 Answers

Connecting to port 0 is not possible, see

It is a special port allowing programs to obtain random port for outgoing connection, and should not be used for incoming connections

Therefore, use -p 1-65535 for nmap, especially if you are using TCP or UDP scans

As for /24 notation that is entirely different thing: it is called CIDR notation and used to match range of hosts on network. For instance, 192.168.0.0/24 will specify all addresses between 192.168.0.0 to 192.168.0.255

4

Nmap can scan all TCP UDP ports. You must to know subnetting and network knowledge. 0 port is not a standart port. For subnet if you use 24 subnetmask you will not scan 192.168.0.0 address because 24 subnetmask have a useable range for hosts. 0.0 is out of subnet useable scope. You can learn from here:

Your Answer

Sign up or log in

Sign up using Google Sign up using Facebook Sign up using Email and Password Submit

Post as a guest

Post Your Answer Discard

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy