>>查看或者修改telnet端口.

less /etc/services

或者

vi /etc/services

内容如下:

[root@cdc_conf7 ~]# less /etc/services

# /etc/services:

# $Id: services,v 1.48 2009/11/11 14:32:31 ovasik Exp $

#

# /etc/services:

# $Id: services,v 1.48 2009/11/11 14:32:31 ovasik Exp $

#

# Network services, Internet style

# IANA services version: last updated 2009-11-10

#

# Note that it is presently the policy of IANA to assign a single well-known

# port number for both TCP and UDP; hence, most entries here have two entries

# even if the protocol doesn't support UDP operations.

# Updated from RFC 1700, ``Assigned Numbers'' (October 1994). Not all ports

# are included, only the more common ones.

#

# The latest IANA port assignments can be gotten from

# http://www.iana.org/assignments/port-numbers

# The Well Known Ports are those from 0 through 1023.

# The Registered Ports are those from 1024 through 49151

# The Dynamic and/or Private Ports are those from 49152 through 65535

#

# Each line describes one service, and is of the form:

#

# service-name port/protocol [aliases ...] [# comment]

tcpmux 1/tcp # TCP port service multiplexer

tcpmux 1/tcp # TCP port service multiplexer

tcpmux 1/udp # TCP port service multiplexer

rje 5/tcp # Remote Job Entry

rje 5/udp # Remote Job Entry

echo 7/tcp

echo 7/udp

discard 9/tcp sink null

discard 9/udp sink null

systat 11/tcp users

systat 11/udp users

daytime 13/tcp

daytime 13/udp

qotd 17/tcp quote

qotd 17/udp quote

msp 18/tcp # message send protocol

msp 18/udp # message send protocol

chargen 19/tcp ttytst source

chargen 19/udp ttytst source

ftp-data 20/tcp

ftp-data 20/udp

# 21 is registered to ftp, but also used by fsp

ftp 21/tcp

ftp 21/udp fsp fspd

ssh 22/tcp # The Secure Shell (SSH) Protocol

ssh 22/udp # The Secure Shell (SSH) Protocol

telnet 23/tcp

telnet 23/udp

修改其中的telnet部分,把端口改为233, 如下:

telnet 233/tcp

telnet 233/udp