I want to port scanning on telnet port in a range ip . for ex: i want to know is the 23 port open on 127.0.0.1/255 ? what am i going to do ? is there a option for Nmap to do this ? Thanks .
nmap -p 23 127.0.0.0/24
Will scan port 23 on 127.0.0.0-127.0.0.255. The /24 is CIDR notation, more info on that here:
If you're scanning the range of 127.0.0.1/24 - you're only looking on your localhost (and unless you're doing something sorta funky, the only hit you should get is on 127.0.0.1).
Are you sure that's the range you want to scan?
It would be faster to run
netstat -an > openports.txt from a command prompt, then see if 23 is listening.
sorry i cant send a comment but i test the option : nmap -p 23 127.0.0.0/24 and the result is : its looklike dont work well ...
nmap -p 23 188.8.131.52/24
Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2011-08-29 07:10 PDT Nmap finished: 256 IP addresses (0 hosts up) scanned in 20.399 seconds