Cisco Catalyst 6500 IOS Upgrade

Unanswered Question
Aug 20th, 2010

On Sunday we will be having a network planned downtime.  During this time I plan to upgrade the code on several switches within our environment.  I am the head network admin and I want to ensure that I have all my I’s dotted and my t’s crossed.  I have never preformed an upgrade on a Cisco Catalyst 6500 switch, so just wanted to know If someone could point me in the correct direction?  We are currently running a Sup 720/MSFC3, and 2 WS-X6724-SFP line cards.  Can someone please advise as to which IOS I should be looking for?  We are currently running s72033-pk9sv-mz.122-18.SXD3.bin.  I would also like to know the process if it differs from a regular Catalyst switch or Cisco router.

Thanks to all.

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Reza Sharifi Fri, 08/20/2010 - 17:17


The latest IOS on CCO for Sup-720 is "122-33.SXI4a.".  Find out what features you currently use and what other additional feature you are planning to use.  For example, if you are looking to run IPv6 or MPLS in the feature, you would need to run "12.2(33).SXI2 or later.  Use the Cisco feature navigator to look for features and also do a comparison of different revisions.  For example do a comparison between SXH and SXI.  You will see that SXI has a lot more features then SXH.  Also go through the release notes before upgrade to make sure you are aware of specific bugs for specific IOS release.

Good Luck,


Leo Laohoo Fri, 08/20/2010 - 17:21

Particularly with the Sup32/720, no code is "stable".  Reza, and the rest of us, would recommend that you read the Release Guide before you do anything.  Another method is to put the IOS of your choice and test-bench it.

Brandon Lynch Sat, 08/21/2010 - 09:27

Hey Chad,

As the others on this thread indicated, there isn't necessarily a specific release which you should be looking for unless you're seeking new features in the next release which currently aren't available in the IOS you're running now.  If that's the case, you may want to look at the Software Advisor -

Apart from that, the other thing that you want to make sure of is that you select a comparable feature set to the one you're using now.  I checked the Software Download page and you are currently utilizing an advanced IP services set -


Depending on which release you go to, the exact feature set you're using now (pk9sv) may not be listed.  You will probably want something comparable to 'advipservicesk9'.

As far as the upgrade procedure, if you have dual SUPs in this chassis, you can check the following link for a best practice procedure -

This is known as an FSU (Fast Software Upgrade).  If dual SUPs aren't configured, the upgrade procedure will be similar to that of a router where you simply change the boot statement to point to the new image, save the configuration, and reload.

Hope this helps.


Leo Laohoo Sat, 08/21/2010 - 17:57

there isn't necessarily a specific release which you should be looking for unless you're seeking new features

Hi Brandon,

In our case, it's the other way around.  We upgrade to the latest IOS and find out months down the road that there are some features that is very useful on the IOS currently being loaded.


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