Cisco IOS Software Releases 12.2 Mainline

Field Notice: Cisco IOS 12.2 and 12.2T Release Numbering Changes

Updated July 24, 2001

June 14, 2001

Products Affected



Cisco IOS? Release 12.2

Mainline IOS Release

Cisco IOS Release 12.2T

Technology IOS Release

Other Cisco IOS Releases that use 12.2 and 12.2T as the Parent Release

XED or BU ED Releases

Problem Description

Cisco IOS internal build and maintenance release numbering process is changing to avoid future issues when the parent (12.2) and child (12.2T) trains may get out of sync.

Change is occuring after the release of Cisco IOS 12.2(1).


The Cisco IOS interim build number provides information on maintenance versions customers can upgrade to in order to benefit from fixes already resolved in IOS software before the next maintenance release is available. The following examples help illustrate this point:

  • Example One [Interim Builds]: The defect fixes integrated in Interim builds 12.2(0.1), 12.2(0.2), and so on appear in 12.2(1) since the version is less than the number 1.

  • Example #2 [Interim Builds]: The defect fixes integrated in interim builds 12.2(1.1), 12.2(1.2), and so on appear in 12.2(2) since the interim build version is greater than the version 1 and less than the version 2.

Interim Builds

An interim build is a build occuring on the main development branch that is used to integrate new features, products, or bug fixes. All bug fixes integrated in an interim build migrate to subsequent builds and maintenance releases. Interim builds can be used to support customers.

Note:?Note: Cisco support will help determine if an interim build is the correct path to resolve issues. See Product Bulletin - No. 537 for more information on interim builds.

Problem Symptoms

Starting with 12.2/12.2T and child releases, the traditional migration path for certain features/bugfixes may not apply as it did in the past.


Present Changes


    • 12.2(2) will not be built.

    • 12.2(3) will be the next 12.2 mainline maintenance release.

    • 12.2(1)T has been relabeled to 12.2(2)T, there will be no 12.2(1)T.


Cisco IOS 12.2 DDTS Fixed Integration & Upgrade Table

DDTS- Fixed In

Upgrade to 12.2 Maintenance Release

12.2 Images

12.2(0.1) through 12.2(0.5g)



12.2(0.6) through 12.2(2.5)





Cisco IOS 12.2T DDTS Fixed Integration & Upgrade Table

DDTS- Fixed In

Upgrade to 12.2T Maintenance Release

12.2T Images

12.2(0.1)T through 12.2(0.19)T1



12.2(0.20)T through 12.2(3.x)T

12.2(X) Next 12.2T Maintenance Release


More 12.2 Information

Please review the Cisco IOS Software Roadmap for more information about each IOS Release. Below are links to the Cisco IOS Software Roadmap and to the 12.2 IOS page.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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