Version Numbers

[mrashby]

Can anyone tell me what the number in parens and letters mean in the version numbers of the IOS on cisco devices.

ex: 12.3(7)T and 12.3(4)XD

[Kevin Dorrell]

You can think of the number in brackets as a bug-fix revision. The letters tell you the flavour: T is technology, i.e. the lastest stuff, but maybe not as stable. Not sure offhand what the XD train is about.

Here are a couple of documents for you to read:

http://www.cisco.com/en/US/products/sw/iosswrel/ps5187/products_data_sheet09186a00800a43ed.html

http://www.cisco.com/en/US/products/sw/iosswrel/ps1818/products_tech_note09186a00800b6e23.shtml

http://www.cisco.com/en/US/products/sw/iosswrel/ps5012/products_tech_note09186a00800afdb6.shtml

(I can't count. ;-)

Kevin Dorrell

Luxembourg

[sushilk]

Hi,

There are 5 types of trains in Cisco IOS:

1) mainline-- Consolidates releases and fixes defects. Inherits features from the parent T train, and does not add additional features-- 12.2, 12.3

2) T --Introduces new features and fixes defects--

12.3T

3) S --Consolidates 12.1E, 12.2 mainline, and 12.0S, which supports high-end backbone routing, and fixes defects--12.0S, 12.2S

4) E-- Targets enterprise core and SP edge, supports advanced QoS, voice, security, and firewall, and fixes defects -- 12.1E

5) B-- Supports broadband features and fixes defects-- 12.2B, 12.3B

Then comes Cisco IOS Releases:

*Maintenance Release Naming:

Take an example of 12.2(3)T

12.2 is the Train Number, (3) is the maiintenance release, T is train identifier.

*Rebuild Release Naming:

A numeric suffix in a release name, such as 12.2(8)T1, indicates a rebuild of a maintenance release on a B, S, T, or E train. The 1 after T is Rebuild Number.

*Specific releases:

Identifier Target Technology or Platform

X Varies, one time release

Y Varies, one time release

Z Varies, one time release

A Aggregation/Access Server/Dial

D xDSL

H SDH/SONET

J Aironet Wireless Networking

M Mobile Wireless

W ATM/LAN Switching/Layer 3 Switching

Go through the following link it will give you a fair idea as it might be confusing what I have written without explanation.

Hope this will help you.

[mrashby]

sushilk,

You have basically answered every question I had about the version numbers. I will still check the link but you have put it in terms that are simple and now I understand. Thanks.

[sushilk]

Hi,

I think i forgot to provide the URL.

Here it is-

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

This will give you a better picture.