3825 IOS upgrade

[abbas.wasim]

Cisco 3825 running advanced IP Services and the Version is 12.4(11t). The IPS is not working properly, someone recommend they upgrade to a later version.What damage can be done by upgrading to a later version?

[paul.matthews]

Generally things improve as you go to a later version, but a degree of that is how much later, and what version.

You are on 12.4T - a T-Train is a technology train - where new features first see light of day. That does have an impact upon the stability of the software. The latest 12.4T is 12.4.15T1. That may have new bug fixes, and it may introduce more features that may or may not have issues in your network.

What I would do from here is first off do a bug search to see if there is anything specific that is mentioned that matches the problem you are having (in what way is IPS not working properly).

I would also check the release notes for later versions, looking for specifics that may either help my problem, or may mean a particular version is not a good idea in my network. With that info I would consider the upgrade. Even if there is no *specific* reason to upgrade I would consider doing it as long as I didn't find a reason not to.

I would then consider using whatever my support route is - either contact the partner I use for support or TAC if supported directly by Cisco.

Paul.

[abbas.wasim]

thanks for your reply Paul, well my customer is using SDM 2.4 to configure IPS and get error "IPS may not be working properly on 12.4(11)T and 12.4(11)T1 images. It is recommended to upgrade the router's image to 12.4(11)T2 or later"

or Shall he try SDM 2.0 with current IOS which is 12.4(11)T

[paul.matthews]

Ah! That is interesting - I don't like going backwards if I can avoid it, but that message suggests the T2 may be important. I would read the release notes for 12.4.11T2 to see what has changed, and try 12.4.11T2.

My standard advice to anyone running a T train is to go to the next mainline when practical. I always avoid a .1 of anything if I possibly can. So, this bit is long term - look to move to aroung 12.5(3) or (4) when they are available. Mainline releases are more likely to be stable than T, but I would let the first few releases go to allow timeto stabilise.

Paul.

[abbas.wasim]

Thanks again Paul,

A silly question, what do we normaly call a mainline release?

Regards

[paul.matthews]

Not a silly question at all.

Mainline basically means no letters on the end - 12.4(11) is mainline as an example. Only mainline releases will reach GD - general deployment.

With the specifics mentioned here, 12.4(T) is likely to be a major contributor to 12.5

Paul.