【网络成长记】nc常用命令

-u, --udp                  Use UDP instead of default TCP
-v, --verbose              Set verbosity level (can be used several times)     
-z                         Zero-I/O mode, report connection status only    
-l, --listen               Bind and listen for incoming connections   
-w, --wait <time>          Connect timeout 

nc -vz -w3 11.254.0.1 443

nc -luv 0.0.0.0 53
nc -uv 0.0.0.0 53
nc -uvz 0.0.0.0 53