为了能让cisco交换的远程连接对于账号密码的安全性有所提高，可以用ssh方式连接终端，但是很多出厂的交换机默认的ios是不支持ssh这个功能的，为了能让cisco交换机支持ssh，必须升级带“K9”的IOS.下面是出厂cisco 3750G-24TS默认ios的截图
3750
交换机支持
SSH
需要
12.1
（
11
）
EA1
以上版本软件。
emi是增强型多层镜像，也就是对路由协议的支持更全；而smi是标准多层镜像。
特性集共有三种：
IP BASE
、
IP Services
和
Advanced IP Services
。
- IP BASE：支持第2层转发和基本的第3层路由，包括EIGRP stub模式。
- IP Services：包括IP BASE特性集，支持高级第3层路由，如OSPF和组播路由。
- Advanced IP Services：包括IP Services，支持IPv6功能。
解决方案步骤：
1.
从
cisco
官网下载
ios
2.
升级
ios
3.
配置交换机支持
ssh
从cisco官网下载ios
打开cisco官网
http://www.cisco.com找到products&services 点击选择cisco ios and nc-os software
也可以直接打开以下链接：
http://tools.cisco.com/support/downloads/go/Redirect.x?mdfid=282504484
会跳出登录界面
未注册的用户根据注册信息填写就行，但有一点就是邮箱一定要填写正确，因为注册后会发一份邮件到您的邮箱去激活才可以使用
接下来登录进去，选择后缀带
SE
版本就会自动链接其他页面去了
跳转下一个页面如下，选择要找交换机型号
跳转下一个页面如下，点解下载软件
跳转下一个页面如下，选择最新版本下载。但根据经验的话，最好选择最新版本后退一两个版本。这里我们选择最新
IOS
版本，并下载带“
K9
”字符的
ios
……………………………………………………省略
跳转下一个页面如下
跳转下一个页面如下
这样
c3750-ipbasek9-mz.122-53.SE3.bin
就下载来。后来发现！由于在应用中，
cisco 3750G
需支持其他一些路由协议。所以我这里就以
c3750-ipservicesk9-mz.122-50.SE3.bin
为升级版本
IOS
提供一个非官网下载链接：
ftp://87.241.226.154/3750/c3750-ipservicesk9-mz.122-50.SE3.bin
11.6 MB
大小
CISCO Server TFTP 下载地址：
http://www.skycn.com/soft/18565.html#downUrlMap
这里以CISCO Server TFTP升级方式，如下图
拷贝
c3750-ipservicesk9-mz.122-50.SE3.bin
到TFTP目录下面
升级ios
3750G(config)#interface vlan 1
3750G(config-if)#ip add
3750G(config-if)#ip address 192.168.100.2 255.255.255.0
3750G(config-if)#end
3750G#ping 192.168.100.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.100.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
3750G#dir
Directory of flash:/
3 -rwx 1754 Feb 5 2010 16:40:45 +00:00 config.text
4 -rwx 5 Feb 5 2010 16:40:45 +00:00 private-config.text
7 drwx 192 Mar 1 1993 00:07:31 +00:00 c3750-ipbase-mz.122-35.SE5
32514048 bytes total (22883840 bytes free)
3750G#delete/force(
不再询问确认
) /recursive(
删除目录下的子目录和文件
) c3750-ipbase-mz.122-35.SE5
3750G#copy tftp flash （从tftp下载ios）
Address or name of remote host
192.168.100.1 输入tftp地址
Source filename
c3750-ipservicesk9-mz.122-50.SE3.bin ios名称
Destination filename [c3750-ipservicesk9-mz.122-50.SE3.bin]
回车
Accessing tftp://192.168.100.1/c3750-ipservicesk9-mz.122-50.SE3.bin...
Loading c3750-ipservicesk9-mz.122-50.SE3.bin from 192.168.100.1 (via Vlan1):
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 12239852 bytes]
3750G#conf t
Enter configuration commands, one per line. End with CNTL/Z.
3750G(config)#boot system flash:c3750-ipservicesk9-mz.122-50.SE3.bin
设置启动c3750-ipservicesk9-mz.122-50.SE3.bin为新IOS
3750G(config)#exit
3750G#wr
*Mar 1 03:59:40: %SYS-5-CONFIG_I: Configured from console by consoler
Building configuration...
[OK]
3750G#reload
Proceed with reload? [confirm]
回车
*Mar 1 03:59:51: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.
Base ethernet MAC Address: 3c:df:1e:c4:a1:00
Xmodem file system is available.
The password-recovery mechanism is enabled.
Initializing Flash...
flashfs[0]: 501 files, 7 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 32514048
flashfs[0]: Bytes used: 21870080
flashfs[0]: Bytes available: 10643968
flashfs[0]: flashfs fsck took 8 seconds.
...done Initializing Flash.
Boot Sector Filesystem (bs) installed, fsid: 3
done.
Loading "flash:c3750-ipservicesk9-mz.122-
50.SE3.bin"...@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
File "flash:c3750-ipservicesk9-mz.122-50.SE3.bin" uncompressed and installed, entry point: 0x1000000
executing...
Restricted Rights Legend
Use, duplication, or disclosure by the Government is
subject to restrictions as set forth in subparagraph
(c) of the Commercial Computer Software - Restricted
Rights clause at FAR sec. 52.227-19 and subparagraph
(c) (1) (ii) of the Rights in Technical Data and Computer
Software clause at DFARS sec. 252.227-7013.
cisco Systems, Inc.
170 West Tasman Drive
San Jose, California 95134-1706
Cisco IOS Software, C3750 Software (C3750-IPSERVICESK9-M), Version 12.2(50)SE3, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by Cisco Systems, Inc.
Compiled Wed 22-Jul-09 06:19 by prod_rel_team
Image text-base: 0x01000000, data-base: 0x02D00000
Initializing flashfs...
flashfs[1]: 501 files, 7 directories
flashfs[1]: 0 orphaned files, 0 orphaned directories
flashfs[1]: Total bytes: 32514048
flashfs[1]: Bytes used: 21870080
flashfs[1]: Bytes available: 10643968
flashfs[1]: flashfs fsck took 2 seconds.
flashfs[1]: Initialization complete....done Initializing flashfs.
Checking for Bootloader upgrade.. upgrading.. writing boot sectors..done.
The system will now restart
Boot Sector Filesystem (bs) installed, fsid: 2
Base ethernet MAC Address: 3c:df:1e:c4:a1:00
Xmodem file system is available.
The password-recovery mechanism is enabled.
Initializing Flash...
……………………………………………………………….
中间省略
Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 28 WS-C3750G-24TS-1U
12.2(50)SE3 C3750-IPSERVICESK9-M
说明升级成功了
Press RETURN to get started!
配置交换机支持ssh
3750G(config)# enable secret viong
3750G(config)#username viong password 123456
3750G(config)# line vty 0 4
3750G(config-line)#login local
3750G(config-line)#transport input ssh
设置让
cisco
交换机支持
SSH
连接
也许就那么几个步骤！有点画蛇添足写这么多。请别嫌弃我
但为了规范点，还是辛苦点整理出来。