1, edit config file, vim /etc/xinetd.d/krb5-telnet

# default: off
# description: The kerberized telnet server accepts normal telnet sessions, \
# but can also use Kerberos 5 authentication.
service telnet
{
flags = REUSE
socket_type = stream
wait = no
user = root
server = /usr/kerberos/sbin/telnetd
log_on_failure += USERID
disable = yes
}

make “disable=yes” to “disable=no”

2,restart service

service xinetd restart

3,check port

netstat -an | grep 23

4,telnet this server by other server

[weblogic@v0A-123-177-201 ~]$ telnet 10.123.100.244 23
Trying 10.123.100.244...
Connected to bogon (10.123.100.244).
Escape character is '^]'.

v0A-123-100-244 (Linux release 2.6.18-194.el5xen #1 SMP Tue Mar 16 22:01:26 EDT 2010) (2)

login:
telnet> quit
Connection closed.