1

Is there any reason why an -sS scan (or most others) would not report an open port that doesn't have a service attached to it?

For example, in a regular -sS scan, the following port will be missing, but when I scan that port specifically, it appears as open.

PORT STATE SERVICE

2509/tcp open unknown

6

Most likely, it's because port 2509 isn't in the 1000 most frequently used TCP ports. Unless you specify specific ports or a port ratio or top port number, nmap scans only the 1000 most commonly seen ports. See the nmap user guide for details on port selection.

  • Thanks, went back and tried a full port scan and it was successful. Previously had used -p"*" which was wrong syntax. Worked with -p- – Ben Jun 23 '14 at 20:37

Your Answer

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

Not the answer you're looking for? Browse other questions tagged or ask your own question.