說起思科的交換機升級，大多數人想到的是以下幾步：
（1）把系統.bin文件通過TFTP或是FTP上傳到交換機中
（2）將原有.bin文件刪除，重啓（或是手動設置引導順序）
（3）重啓後升級完成。
的確，2960、3560、3750等等交換機的升級都可以通過以上幾點來完成。可是思科的3650交換機升級跟以前的有些不同。
在升級之前，先看一下3650中的dir信息
Switch#dir
Directory of flash:/
15490 -rw- 15954556 Feb 13 2018 00:53:01 +00:00 cat3k_caa-guestshell.16.03.05b.SPA.pkg
15491 -rw- 22301472 Feb 13 2018 00:52:59 +00:00 cat3k_caa-rpbase.16.03.05b.SPA.pkg
15492 -rw- 266035828 Feb 13 2018 00:53:01 +00:00 cat3k_caa-rpcore.16.03.05b.SPA.pkg
15493 -rw- 9089660 Feb 13 2018 00:53:00 +00:00 cat3k_caa-srdriver.16.03.05b.SPA.pkg
15494 -rw- 212812400 Feb 13 2018 00:53:00 +00:00 cat3k_caa-wcm.16.03.05b.SPA.pkg
15495 -rw- 13423224 Feb 13 2018 00:53:00 +00:00 cat3k_caa-webui.16.03.05b.SPA.pkg
15496 -rw- 4748 Feb 13 2018 00:53:24 +00:00 packages.conf
15497 -rw- 629 Jul 31 2018 02:09:08 +00:00 bootloader_evt_handle.log
15498 drwx 4096 Feb 13 2018 00:59:14 +00:00 core
54209 drwx 4096 Feb 13 2018 00:55:52 +00:00 .prst_sync
69697 drwx 4096 Feb 13 2018 00:55:53 +00:00 .rollback_timer
77441 drwx 4096 Jul 31 2018 02:09:22 +00:00 dc_profile_dir
77443 drwx 4096 Feb 13 2018 00:56:02 +00:00 gs_script
15499 -rw- 65301 Jul 31 2018 02:09:39 +00:00 memleak.tcl
15500 drwx 4096 Feb 13 2018 00:56:31 +00:00 .installer
15502 -rw- 2097152 Jul 31 2018 02:12:32 +00:00 nvram_config
15503 -rw- 2097152 Jul 31 2018 02:12:32 +00:00 nvram_config_bkup
15504 -rw- 35 Jul 30 2018 06:29:18 +00:00 pnp-tech-time
15505 -rw- 54759 Jul 30 2018 06:29:21 +00:00 pnp-tech-discovery-summary
在這裏你會發現這裏沒有.bin文件了。
雖然如此，但是在這裏升級仍然需要使用到.bin文件，因爲你從思科網站上下載的升級文件就是.bin的。下面我們說一下具體步驟：
1、從網站上下載所需要的升級文件，文件擴展名是.bin。
2、通過TFTP上傳到交換機中，如下：
Switch#copy tftp://10.0.0.2/cat3k_caa-universalk9.16.03.06.SPA.bin flash:
Destination filename [cat3k_caa-universalk9.16.03.06.SPA.bin]?
Accessing tftp://10.0.0.2/cat3k_caa-universalk9.16.03.06.SPA.bin...
Loading cat3k_caa-universalk9.16.03.06.SPA.bin from 10.0.0.2 (via GigabitEthernet1/0/2): !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 537577577 bytes]
537577577 bytes copied in 211.316 secs (2543951 bytes/sec)
3、與之前升級不同的就是在這裏，執行以下命令進行安裝
Switch#request platform software package install switch all file flash:cat3k_caa-universalk9.16.03.06.SPA.bin
--- Starting install local lock acquisition on switch 1 ---
Finished install local lock acquisition on switch 1
Expanding image file: flash:cat3k_caa-universalk9.16.03.06.SPA.bin
[1]: Expanding file
[1]: Finished expanding all-in-one software package in switch 1
SUCCESS: Finished expanding all-in-one software package.
[1]: Performing install
SUCCESS: install Finished
[1]: install package(s) on switch 1
--- Starting list of software package changes ---
Old files list:
Removed cat3k_caa-guestshell.16.03.05b.SPA.pkg
Removed cat3k_caa-rpbase.16.03.05b.SPA.pkg
Removed cat3k_caa-rpcore.16.03.05b.SPA.pkg
Removed cat3k_caa-srdriver.16.03.05b.SPA.pkg
Removed cat3k_caa-wcm.16.03.05b.SPA.pkg
Removed cat3k_caa-webui.16.03.05b.SPA.pkg
New files list:
Added cat3k_caa-guestshell.16.03.06.SPA.pkg
Added cat3k_caa-rpbase.16.03.06.SPA.pkg
Added cat3k_caa-rpcore.16.03.06.SPA.pkg
Added cat3k_caa-srdriver.16.03.06.SPA.pkg
Added cat3k_caa-wcm.16.03.06.SPA.pkg
Added cat3k_caa-webui.16.03.06.SPA.pkg
Finished list of software package changes
SUCCESS: Software provisioned. New software will load on reboot.
[1]: Finished install successful on switch 1
Checking status of install on [1]
[1]: Finished install in switch 1
SUCCESS: Finished install: Success on [1]
其實到這裏升級就完成了一半兒，因爲上面提示：New software will load on reboot.也就是說重啓之後就是以新的系統啓動了。
這時我們再用dir查看一下：
Switch#dir
Directory of flash:/
15490 -rw- 15954556 Feb 13 2018 00:53:01 +00:00 cat3k_caa-guestshell.16.03.05b.SPA.pkg
15491 -rw- 22301472 Feb 13 2018 00:52:59 +00:00 cat3k_caa-rpbase.16.03.05b.SPA.pkg
15492 -rw- 266035828 Feb 13 2018 00:53:01 +00:00 cat3k_caa-rpcore.16.03.05b.SPA.pkg
15493 -rw- 9089660 Feb 13 2018 00:53:00 +00:00 cat3k_caa-srdriver.16.03.05b.SPA.pkg
15494 -rw- 212812400 Feb 13 2018 00:53:00 +00:00 cat3k_caa-wcm.16.03.05b.SPA.pkg
15495 -rw- 13423224 Feb 13 2018 00:53:00 +00:00 cat3k_caa-webui.16.03.05b.SPA.pkg
15509 -rw- 4737 Jul 31 2018 02:37:29 +00:00 packages.conf
15497 -rw- 666 Jul 31 2018 02:21:44 +00:00 bootloader_evt_handle.log
15498 drwx 4096 Feb 13 2018 00:59:14 +00:00 core
54209 drwx 4096 Feb 13 2018 00:55:52 +00:00 .prst_sync
69697 drwx 4096 Feb 13 2018 00:55:53 +00:00 .rollback_timer
77441 drwx 4096 Jul 31 2018 02:21:58 +00:00 dc_profile_dir
77443 drwx 4096 Feb 13 2018 00:56:02 +00:00 gs_script
15499 -rw- 65301 Jul 31 2018 02:22:15 +00:00 memleak.tcl
15500 drwx 4096 Feb 13 2018 00:56:31 +00:00 .installer
15502 -rw- 2097152 Jul 31 2018 02:25:06 +00:00 nvram_config
15503 -rw- 2097152 Jul 31 2018 02:25:06 +00:00 nvram_config_bkup
15504 -rw- 35 Jul 30 2018 06:29:18 +00:00 pnp-tech-time
15505 -rw- 54759 Jul 30 2018 06:29:21 +00:00 pnp-tech-discovery-summary
15496 -rw- 0 Jul 31 2018 02:37:52 +00:00 .onreboot
15511 -rw- 15950464 Jul 31 2018 02:36:20 +00:00 cat3k_caa-guestshell.16.03.06.SPA.pkg
15516 -rw- 22302593 Jul 31 2018 02:36:25 +00:00 cat3k_caa-rpbase.16.03.06.SPA.pkg
15512 -rw- 265124472 Jul 31 2018 02:36:21 +00:00 cat3k_caa-rpcore.16.03.06.SPA.pkg
15514 -rw- 9095808 Jul 31 2018 02:36:23 +00:00 cat3k_caa-srdriver.16.03.06.SPA.pkg
15510 -rw- 4737 Jul 31 2018 02:37:15 +00:00 cat3k_caa-universalk9.16.03.06.SPA.conf
15515 -rw- 211675764 Jul 31 2018 02:36:25 +00:00 cat3k_caa-wcm.16.03.06.SPA.pkg
15513 -rw- 13423228 Jul 31 2018 02:36:23 +00:00 cat3k_caa-webui.16.03.06.SPA.pkg
15508 -rw- 4748 Jul 31 2018 02:37:29 +00:00 packages.conf.00-
1621966848 bytes total (453984256 bytes free)
通過上面的顯示可以看出flash中已經安裝了新版本的系統，但是老版本的系統仍然在。那麼該如何刪除老版本的系統釋放系統空間呢？我們往下繼續
4、重啓交換機，重啓之後交換機會以新版本的系統啓動
Cisco IOS Software [Denali], Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 16.3.6, RELEASE SOFTWARE (fc3)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2018 by Cisco Systems, Inc.
Compiled Wed 28-Feb-18 15:23 by mcpre
上面顯示已經從16.3.6啓動了，緊接着我們可以通過下面的命令來釋放系統空間：
Switch#request platform software package clean switch all file flash:
Running command on switch 1
Cleaning up unnecessary package files
Scanning boot directory for packages ... done.
Preparing packages list to delete ...
packages.conf
File is in use, will not delete.
cat3k_caa-guestshell.16.03.06.SPA.pkg
File is in use, will not delete.
cat3k_caa-rpbase.16.03.06.SPA.pkg
File is in use, will not delete.
cat3k_caa-rpcore.16.03.06.SPA.pkg
File is in use, will not delete.
cat3k_caa-srdriver.16.03.06.SPA.pkg
File is in use, will not delete.
cat3k_caa-wcm.16.03.06.SPA.pkg
File is in use, will not delete.
cat3k_caa-webui.16.03.06.SPA.pkg
File is in use, will not delete.
done.
The following files will be deleted:
[1]:
/flash/cat3k_caa-guestshell.16.03.05b.SPA.pkg
/flash/cat3k_caa-rpbase.16.03.05b.SPA.pkg
/flash/cat3k_caa-rpcore.16.03.05b.SPA.pkg
/flash/cat3k_caa-srdriver.16.03.05b.SPA.pkg
/flash/cat3k_caa-universalk9.16.03.06.SPA.conf
/flash/cat3k_caa-wcm.16.03.05b.SPA.pkg
/flash/cat3k_caa-webui.16.03.05b.SPA.pkg
/flash/packages.conf.00-
Do you want to proceed? [y/n]y
[1]:
Deleting file flash:cat3k_caa-guestshell.16.03.05b.SPA.pkg ... done.
Deleting file flash:cat3k_caa-rpbase.16.03.05b.SPA.pkg ... done.
Deleting file flash:cat3k_caa-rpcore.16.03.05b.SPA.pkg ... done.
Deleting file flash:cat3k_caa-srdriver.16.03.05b.SPA.pkg ... done.
Deleting file flash:cat3k_caa-universalk9.16.03.06.SPA.conf ... done.
Deleting file flash:cat3k_caa-wcm.16.03.05b.SPA.pkg ... done.
Deleting file flash:cat3k_caa-webui.16.03.05b.SPA.pkg ... done.
Deleting file flash:packages.conf.00- ... done.
SUCCESS: Files deleted.
Switch#
這時再用dir查看就會發現老版本的系統已經刪除了，這時3650已經升級完成了。
說明：升級系統前最好先查看一下官方文檔，不過我查看3650升級的官方文檔時發現，文檔中把第四步放在了上傳文件之前，按照他們的說法是先發釋放一下系統空間，不過如果你真按照那樣做了就會發現，那樣釋放空間是行不通的！爲什麼行不通，留給你思考了，不過其實答案就在這篇文章中……