可以使用以下工具测试目标UDP端口是否开放：
Nmap
nmap -sU -p [端口号] [目标IP]
Netcat
nc -zu [目标IP] [端口号]
Hping
hping3 -2 -c 1 [目标IP] -p [端口号]
PortQry
portqry -n [目标IP] -p UDP -e [端口号]
Check ，下载（Linux）
OPTIONS:
-h, –help Print options and usage information.
-n, –noexit Continue processing hostnames on failure.
-p, –port port Port number (default: 80).
-s, –silent Suppress terminal output.
-t, –timeout seconds Timeout for the connection (default: 5).
–tcp TCP probe mode (default).
–udp UDP probe mode.
-v, –version Print current version number.
EXIT CODE:
0 SUCCESS: Port is open on the specified host.
1 FAILURE: Port is closed on the specified host.
2 ERROR: Option parsing error.
3 ERROR: Option argument missing.
4 ERROR: Invalid option argument.
5 ERROR: GNU getopt not found on PATH.
6 ERROR: Multiple probe modes.
7 ERROR: General or unknown error.
EXAMPLES:
check “www.travismclarke.com” “www.google.com” –port 443 –timeout 3
PortforwardCheck，下载（Win）
