1、System Settings→Security Level，打开Securty Level Configuration，在Firewall Options中检查Telnet是否已被选中，如果没有则选中。
2、编辑/etc/xinetd.d/下面的krb5-telnet，如下：
# 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
}
# 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
}
3、System Settings→Server Settings→Services，在服务列表中找到xinetd，重新启动。
重新使用telnet远程登录，应该就可以连上了。