修改的是 /etc/ssh/sshd_config 文件
[root@linux ~]# vi /etc/ssh/sshd_config
#       $OpenBSD: sshd_config,v 1.69 2004/05/23 23:59:53 dtucker Exp $
# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.
# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin
# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.
Port 8284      //以前这个前面是有 # 号的，而且默认是 22 ，修改一下就ok了
#Protocol 2,1
#ListenAddress 0.0.0.0
#ListenAddress ::
# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key

重起ssh服务，修改端口才生效
[root@linux ~]# /etc/init.d/sshd restart
Stopping sshd:                                             [ OK ]
Starting sshd:                                             [ OK ]
[root@linux ~]#
为了检验是否正确，可以使用 netstat -an 命令查看一下。