在安装完毕linux，默认的情况下ssh是开放的，容易受到黑客攻击，简单，有效的操作之一就是修改默认端口号
如下列，我们把22修改我2501
就是修改/etc/ssh/sshd_config //注意，容易和ssh_config相混合
步骤一
[root@localhost ssh]# more sshd_config
# $OpenBSD: sshd_config,v 1.69 2004/05/23 23:59:53 dtucker Exp $
# $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.
# 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.
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.
#Port 22 //先把22注释掉
port 2501 //添加一个新的端口
#Protocol 2,1
port 2501 //添加一个新的端口
#Protocol 2,1
步骤二
[root@localhost ~]# service sshd restart
Stopping sshd:[ OK ]
Starting sshd:[ OK ]
Stopping sshd:[ OK ]
Starting sshd:[ OK ]
步骤三
用SecureCRT测试
