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New Member

how to select a IOS for upgradation

It would be quite helpful to me if u suggest how to select a IOS for upgradation for the below scenarios.

Currently I have 4 switches to upgrade for ssh feature, below are the existing IOS images.






So please suggest the guidelines to select the correct image & which are the important things I have to keep in my mind while selecting the IOS image.


Re: how to select a IOS for upgradation

Generally they will tell you to take the latest code as long as its not a deferred image for some reason . Look for major bugs using the bug toolkit .


Re: how to select a IOS for upgradation

Here's how to read the code versions:

x.y(zz)AB Example: 12.2(40)SE2 (on your CBS)

X=Major Version (11, 12, or 15)

y=Minor Version (0,1,2,3, or 4)

ZZ=support for specific hardware/features

A=Branch (SB=Service Provider)

B=Maintenance release (Bug Fixes)

Basically, you want the newest release that supports all the features you need, with the highest Maint number at the end.

For example, for the 3560, you could pick:





The all have the same major and minor version. So looking at the number in parentheses you need to decide which one supports the features you need. If they all do, then next step. Look at the number at the end. If there is no number, then it's the first release. If you were to compare it to windows, that would be without a service pack.

My choice here would most likely be 12.2(44)SE6. Then I would go to the Cisco site and see what bugs are open on that code, and see if they would affect me.

A risk analysis is always a good idea when installing any new code not just Cisco code.

New Member

Re: how to select a IOS for upgradation

Thanks for yr reply.

As u have suggested the above version,but all of the above version are comes with following types,such as :

1.Advanced ip services

2.ip services

3.ip base

Also many types are there........

So can u suggest me which one to choose & why.

Can I get these versions free of cost or, I have to pay for it.

If I will go for the latest one, there anything extra I have to pay in term of its price.


Re: how to select a IOS for upgradation

Your only allowed to upgrade to the "feature set" you already have. If you want to upgrade from IP Base to IP Advanced services, you need to pay.


Re: how to select a IOS for upgradation


In addition to the other posters suggestions I will add this in order for you to ahve SSH:

1. For 3560 you will need a k9 in the image name, i.e. c3560-ipbasek9-mz.122-xxxx

2. For 2950 you will need a c2950-i6k2l2q4-mz.121-22.EA13.bin

3. For CBS3020 the same as for 3560 - you need a k9 image; i.e. cbs30x0-lanbasek9-mx.122-xxxxx

4. For Cat2900XL and 3500XL it is not possible to get SSH support, as far as I know.

HTH, Ingolf