in reply to Re^2: IP address validation when IP is picked dynamically
in thread IP address validation when IP is picked dynamically

That's not sufficient. There is probably whitespace at the end of $parameter_value:
print "Failed -> $key:$parameter_value<<<\n"

Please read the Basic debugging checklist.

Print a full $line and post it.

Are you using the latest version of Data::Validate::IP from CPAN?