crackerbox$ nc -v -v -w 4 -u -z target.example.net 7 9 13 18 19 \
               21 37 50 53 67-70
target.example.com [192.168.20.28] 7 (echo) open
target.example.com [192.168.20.28] 9 (discard) open
target.example.com [192.168.20.28] 13 (daytime) : Connection refused
target.example.com [192.168.20.28] 18 (msp) : Connection refused
target.example.com [192.168.20.28] 19 (chargen) : Connection refused
target.example.com [192.168.20.28] 21 (fsp) : Connection refused
target.example.com [192.168.20.28] 37 (time) open
target.example.com [192.168.20.28] 50 (re-mail-ck) : Connection refused
target.example.com [192.168.20.28] 53 (domain) open
target.example.com [192.168.20.28] 70 (gopher) : Connection refused
target.example.com [192.168.20.28] 69 (tftp) : Connection refused
target.example.com [192.168.20.28] 68 (bootpc) : Connection refused
target.example.com [192.168.20.28] 67 (bootps) open