默认在CentOS-Minimal版本下没有安装telnet和xinetd服务。
1、安装telnet
[root@localhost ~]# rpm -qa | grep telnet –检查是否安装telnet，没有文件表示未安装
[root@localhost ~]# yum -y install telnet –安装telnet客户端，出现“Complete!”表示安装完成
[root@localhost ~]# yum -y install telnet-server –安装telnet服务端，出现“Complete!”表示安装完成
2、安装xinetd
[root@localhost ~]# rpm -qa | grep xinetd –检查是否安装xinetd，没有文件表示未安装
[root@localhost ~]# yum -y install xinetd –安装xinetd，出现“Complete!”表示安装完成
3、在xinetd服务中开启telnet服务
[root@localhost ~]# vi /etc/xinetd.d/telnet –编辑
# default: yes
# description: The telnet server servestelnet sessions
# unencrypted username/password pairs for authentication
service telnet
{
flags = REUSE
socket_type = stream
wait = no
user = root
server =/usr/sbin/in.telnetd
log_on_failure += USERID
disable = no
}
4、启动xinetd服务
[root@localhost ~]# systemctl restart xinetd.service –启动服务
[root@localhost ~]# ps -ef | grep xinetd –查看启动
5、设置开机启动xinetd
[root@localhost ~]# chkconfig –level 35 xinetd on
Note: Forwarding request to ‘systemctl enable xinetd.service’.
[root@localhost ~]# systemctl enable xinetd.service
[root@localhost ~]# chkconfig –list –查看
6、测试telnet
[root@localhost ~]# telnet 127.0.0.1
telnet下root登录，密码正确，总提示：Login incorrect
[root@localhost ~]# vi /etc/pam.d/remote
注释/etc/pam.d/remote的第一行，即：auth required pam_securetty.so
关闭防火墙
[root@localhost ~]# systemctl status firewalld.service –再查看防火墙状
[root@localhost ~]# systemctl stop firewalld.service –关闭防火墙
[root@localhost ~]# systemctl disable firewalld.service –永久关闭防火墙
本文永久更新链接地址：https://www.linuxidc.com/Linux/2018-05/152335.htm
