This option specifies which ports you want to try to connect to.
It can be a single port, a comma-separated list of
ports (e.g. 80,443,8080), a range
(e.g. 1-1023), and any combination
of those (e.g. 21-25,80,443,1024-2048).
The beginning and/or end values
of a range may be omitted, causing Nping to use 1 and 65535,
respectively. So you can specify -p- to target ports from 1 through
65535. Using port zero is allowed if you specify it explicitly.
This option asks Nping to use the specified port as source port for
the TCP connections. Note that this might not work on all systems or
may require root privileges. Specified value must be an integer in
the range [0–65535].