centos 7.4关闭111端口
2018-02-26netstat -ntlp检查有个111端口，对应进程1/systemd 。
111端口的进程是systemd，实际用的是rpcbind。大部分服务是不依赖于rpcbind的，只有NFS需要用到这个服务，所以可以禁掉。
systemctl disable rpcbind.service
systemctl disable rpcbind.socket
systemctl stop rpcbind.service
systemctl stop rpcbind.socket
systemctl stop nfs-mountd.service
systemctl disable nfs-mountd.service
systemctl stop systemd-resolved.service
systemctl disable systemd-resolved.service
systemctl stop httpd.socket
systemctl stop httpd.service