Debug 网络服务是否开启 tcp: telnet {ip} {port} nc -z {ip} {port} udp: nc -uz {ip} {port} strace # install yum install centos-release-scl-rh -y yum install strace --enablerepo=centos-sclo-rh -y # 命令追踪，例如df -h卡顿 strace df -h