Possible bug?

[Shaun Michelson via dev <dev () nmap org>]

I have come across a case where, if you open port 443 on a public facing interface, nmap will report dozens of other 
open ports on that host. If you then close port 443, nmap cannot detect the host at all. I have replicated on multiple 
hosts running both Ubuntu and Windows Server OS.

Attached are the results of an example nmap scan on a machine with a single port open (443), the results of which show 
dozens of other ports open.

Also attached are a port probe using grc.com ShieldsUp service, the results of which show only port 443 open, as 
expected.

Just checking to see if anyone is aware of this behavior and if so what is the cause?

Thanks!

Shaun Michelson | Director, Information Technology | Apple Hospitality REIT
Ph: 804.727.6339 | smichelson () applereit com<mailto:smichelson () applereit com>
www.applehospitalityreit.com<http://www.applehospitalityreit.com/>

_______________________________________________
Sent through the dev mailing list
https://nmap.org/mailman/listinfo/dev
Archived at http://seclists.org/nmap-dev/