nc 命令 安装命令1234567yum install -y nc#yum install -y nmap-ncat#模拟端口监听nc -lvnp 9999#查看监听端口netstat -lanp | grep 9999telnet ip 9999 监听端口12345#模拟端口监听nc -lvnp 9999#查看监听端口netstat -lanp | grep 9999telnet ip 9999