1、查看telnet rpm 包
# rpm -qa | grep telnet
2、安装telnet server rpm 包
# rpm -ivh telnet-server-0.17-38.el5.i386.rpm
注：安装完毕以后会在 /etc/xinetd.d/中出现一个telnet配置文件
3.查看telnet 服务
# chkconfig --list | grep telnet
开启telnet 服务
# chkconfig telnet on
4.配置telnet 文件
[root@test]# vim /etc/xinetd.d/telnet
service telnet
{
disable = no
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/sbin/in.telnetd
log_on_failure += USERID
}
5.telnet开启root访问
确认/etc/pam.d/login 中的pam_securetty.so行，并将其注释掉 "#"
[root@test]# vim /etc/pam.d/login
#%PAM-1.0
#auth [user_unknown=ignore success=ok ignore=ignore default=bad] pam_securetty.so
auth include system-auth
account required pam_nologin.so
account include system-auth
password include system-auth
# pam_selinux.so close should be the first session rule
session required pam_selinux.so close
session include system-auth
session required pam_loginuid.so
session optional pam_console.so
# pam_selinux.so open should only be followed by sessions to be executed in the
user context
session required pam_selinux.so open
session optional pam_keyinit.so force revoke
6.开通telnet 控制台，在 /etc/securetty文件中设定
[root@test]# vim /etc/securetty
console
vc/1
vc/2
vc/3
tty1
tty2
tty3
tty4
tty5
...
pts/1
pts/2
pts/3
pts/4
pts/5
在文件后面追加 "pts/1....pts/n"
7.telnet端口更改
设定配置文件 /etc/services
[root@test]# vim /etc/services
找到下面的两行：
telnet 23/tcp
telnet 23/udp
