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New Member

How to Determine which IOS version is new

Hi

When I have a few IOS versions such as 12.3(2) , 12.3.(3)B and 12.3(2)T how do I know out of these three which one is the newest and which one is the oldest?

Also is there a 12.4 for the 2500 series routers?

Your help is much appreciated!

Many thanks!

1 ACCEPTED SOLUTION

Accepted Solutions

Re: How to Determine which IOS version is new

Hi, please refer to the below white paper. The 12.3(2) is mainline release, 12.3(3)B is main line with more software fixes so will effectivley be "newer". The T train indicates "new features" which will not be found in the mainline release.

http://www.ciscosystems.com/en/US/products/sw/iosswrel/ps1828/products_white_paper09186a008018305e.shtml

5 REPLIES
Bronze

Re: How to Determine which IOS version is new

Take a look at the roadmap:

http://www.cisco.com/warp/public/620/roadmap.shtml

That might help you. You can also check the release date to get a general idea.

I do not see any 12.4 for the 2500 series routers.

Stephen

New Member

Re: How to Determine which IOS version is new

Hi Stephen

The link you gave was okay to me and helped me to a certain extend. But it did not have the versions that I was looking for. The idea that I got from the road map is that even though there are different varieties in the same IOS version such as 12.3(2)XF, 12.3(7)XI they are all parellel to each other, aren't they?

Yes you are right, it seems that there is not release of 12.4 for 2500 series.

Thanks in advace!

Re: How to Determine which IOS version is new

Hi, please refer to the below white paper. The 12.3(2) is mainline release, 12.3(3)B is main line with more software fixes so will effectivley be "newer". The T train indicates "new features" which will not be found in the mainline release.

http://www.ciscosystems.com/en/US/products/sw/iosswrel/ps1828/products_white_paper09186a008018305e.shtml

Cisco Employee

Re: How to Determine which IOS version is new

Hi Omal,

To some degree you are comparing apples and oranges here. As mentioned by another poster, IOS is released in several different "trains," and it can be hard to compare between them. So, 12.3(2)T is a (T)echnology train, meaning it has new features and bug fixes integrated with each release. 12.3(2) by itself is a mainline train, which generally just has bug fixes committed. Cisco works on both trains at the same time, integrating bug fixes into mainline code, and new features and bug fixes into the T-train. In addition to "T", other letters are often placed at the end of the IOS release for specialized IOS's for certain product lines, such as the Cat 6K or 10000 series.

So, the short answer would be this: I recommend comparing IOS's within their train and not between trains. There can be substantial differences.

Are you looking at a bug and trying to determine where it is fixed, or is this just a general question?

Jeff McLaughlin, CCIE #14023

Cisco Systems

New Member

Re: How to Determine which IOS version is new

Hi

Thank you so much for all three of you. All three of you said the same thing in three different way which made me understand and clarify my doubt very well. I relly appreciate your help.

Jeff: I just wanted to know this and it was a general question. I wasn't trying to fix a bug.

Thank you so much gentlemen!

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