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Cisco IOS Reference Guide

Table of Contents
White Paper: Cisco IOS Reference Guide........................................................................................................1
1.0 Introduction....................................................................................................................................1
2.0 Cisco IOS Trains............................................................................................................................1
3.0 Cisco IOS Releases........................................................................................................................1
4.0 Cisco IOS Feature Sets..................................................................................................................1
5.0 Cisco IOS Images..........................................................................................................................1
6.0 Tools and Resources.......................................................................................................................1
7.0 Important Communications about Releases...................................................................................1
Related Resources...................................................................................................................................1
1.0 Introduction.................................................................................................................................................2
1.1 Growth of Cisco IOS.....................................................................................................................2
1.2 Scope of this Document.................................................................................................................2
2.0 Cisco IOS Trains.........................................................................................................................................2
2.1 Types of Trains..............................................................................................................................3
2.2
Mainline and T Train Relationship...............................................................................................3
2.3
Train Lifecycle Milestones...........................................................................................................4
3.0 Cisco IOS Releases....................................................................................................................................5
3.1. Types of Releases.........................................................................................................................5
3.2 Maintenance Releases....................................................................................................................5
3.3 Rebuild Releases............................................................................................................................6
3.4 General Deployment (GD) Releases..............................................................................................6
3.5 Special Releases.............................................................................................................................7
3.6 Interim Builds................................................................................................................................9
4.0 Cisco IOS Feature Sets..............................................................................................................................9
4.1. Cisco IOS Packaging....................................................................................................................9
5.0 Cisco IOS Images.....................................................................................................................................10
5.1 Image Naming..............................................................................................................................10
5.2 Images Running on a Router........................................................................................................10
6.0 Tools and Resources.................................................................................................................................11
6.1 Tools............................................................................................................................................11
6.2 Cisco IOS Roadmap.....................................................................................................................11
7.0 Important Communcations about Releases...............................................................................................11

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designing.1 2.2 7. feature sets. releases. This document describes the release model—trains. and managing network infrastructures.0 2. implementing.4 3.0 3.5 4.1 3.2 3.3 3.1 5.0 Introduction 1. For information about how to install or configure Cisco IOS Software.2 2.3 Packaging 5.3 3.1 6.2 Growth of Cisco IOS Scope of this Document 2.0 Tools and Resources Tools Cisco IOS Roadmap Important Communications about Releases Related Resources • Cisco IOS Roadmap • The ABC's of Cisco IOS Software: Understanding the Essentials Series • Cisco IOS Software Technical Documentation Cisco IOS Reference Guide .White Paper: Cisco IOS Reference Guide Understanding the Cisco IOS® Software release model is essential for planning. 1.1 1.1 Cisco IOS Trains Types of Trains Mainline and T Train Relationship Train Lifecycle Milestones Cisco IOS Releases Types of Releases Maintenance Releases Rebuild Releases GD Releases Special Releases Cisco IOS Feature Sets Cisco IOS 12.0 4.0 6. and images.0 Cisco IOS Images 5. see Cisco IOS Software Technical Documentation.2 Image Naming Images Running on a Router 6.

Cisco IOS Reference Guide . From the beginning. and ensuring investment protection.0 Introduction Cisco IOS Software is network system software that tightly integrates a broad range of Internet and enterprise network hardware.0 Cisco IOS Trains A Cisco IOS train is a vehicle for delivering releases that evolve from a common code base. applications. To perform these critical tasks. Today. maximizing ROI. network administrators must understand the following topics: • Feature sets and images • Cisco IOS tools. Cisco routers ran Cisco IOS Software. and an array of hardware that ensures its longevity. 1. optical. In recent years. Cisco IOS Software is the unifying thread that connects otherwise disparate networks to build a scalable network infrastructure. with the addition of thousands of new features. and a wide array of platforms. Cisco IOS Software supports an unparalleled array of features. minimizing costs. As the router market exploded. serving as an end−to−end solution for global networking. It enables network services and Internet applications. such as voice and video over IP networks. hundreds of new applications. storage networking. so did Cisco’s growth. and network services to support e−commerce conducted over multi−service (Data/Voice/Video) applications. wireless.• Software Center: Cisco IOS Software • Cisco IOS Upgrade Planner • Cisco Feature Navigator • What's New for Cisco IOS Software 1. such as Feature Navigator and Upgrade Planner • The Cisco IOS roadmap 2.2 Scope of this Document This document is intended for network administrators who upgrade and maintain a network. network administrators must understand the following topics: • The evolution of Cisco trains and releases • The names of trains and releases • The types of trains and releases To obtain new Cisco IOS images. Cisco IOS Software evolved over time and met the challenge of rapid changes in the business and network environment in the last decade. 1. Customers can leverage their investment in Cisco hardware and software solutions for years. Cisco IOS Software supports new areas of networking technology. Cisco IOS Software diversified from one train of releases to multiple trains supporting different feature sets for different customer needs.1 Growth of Cisco IOS The Internet was a driving force in Cisco’s growth.

such as 12. such as 12.2S E Targets enterprise core and SP edge.1E B Supports broadband features and fixes defects. Cisco could introduce new features in a Cisco IOS release from one train without affecting the code base of the other train.2. and firewall.2. 12. Mainline trains. 12. T Introduces new features and fixes defects. and fixes defects. the need for at least two trains for releasing Cisco IOS Software emerged: • A train for bug fixesmainline • A train for bug fixes and new featuresT train With two trains. are built from previous generation T trains.2. supports advanced QoS.3T S Consolidates 12.3B 2.1 T Train and Mainline Evolution Mainline trains.2B. and 12.0S. 12. 12. Inherits features from the parent T train.2T (see Figure 1). 12.1E. Figure 1: Evolution of T and Mainline Trains Cisco IOS Reference Guide . 12. such as 12.1 Types of Trains Today.0S.3 additional features.2.1T. are parents of other trains. which supports high−end backbone routing. and does not add 12. 12. and fixes defects. 2. voice.2. such as 12. security.2 Mainline and T Train Relationship Early in Ciscos history. Cisco IOS releases are delivered on the following types of trains: Table 1: Types of Trains Train Description Examples mainline Consolidates releases and fixes defects. 12.2 mainline.

2. maintaining. New features are integrated into the T train onlythe mainline train receives bug fixes only.2 Bug Synchronizing and Feature Integration Bug fixes to maintenance releases on a mainline train are synchronized with subsequent maintenance releases on the child T train (see Figure 2). Figure 2: Bug Synchronizing and Feature Integration 2. Cisco IOS Reference Guide .3 Train Lifecycle Milestones At some point in the life of a train. Cisco informs customers that a train has reached one of these milestones by issuing product bulletins and other communications. Cisco stops selling. and supporting it.com FCS Yes Yes* Yes Yes EoS No Yes Yes Yes EoE No No Yes Yes EoL No No No No * FCS corresponds to the first maintenance release on the train. Each new release receives regular maintenance during the early part of the life cycle. The following acronyms are associated with lifecycle milestones: • FCSFirst Customer Shipment • EoSEnd of Sale • EoEEnd of Engineering • EoLEnd of Life The following table briefly describes the train lifecycle milestones. Table 2: Milestones in the Life of a Train Milestone Available through Sales Channels Bug Fixes TAC Support Download from Cisco.2.

3. Maintenance releases typically occur every eight to thirteen weeks. 3. and S trains (see Figure 4).2 mainline train. Figure 4: Maintenance Release Number Sharing Between Mainline. Types of Releases • Maintenance releases • Rebuild releases • General Deployment (GD) releases • Special releases 3. or both. depending on the train.0 Cisco IOS Releases A release is a snapshot in time of the code base of a train.2 Maintenance Releases A maintenance release is a scheduled revision of Cisco IOS Software that introduces new features or bug fixes.2. With the release of the 12. such as 12.1.2(3)T.2. Figure 3: Example of Maintenance Release Name 3.1 Maintenance Release Naming A maintenance release name. and S Trains Cisco IOS Reference Guide . Cisco started sharing a sequence of numbers among maintenance releases on the mainline. T.3.2 Cisco IOS Maintenance Release Revision Number Sharing Bug fixes are synchronized from the mainline to the T train (see Figure 2). T. so customers can determine which T and S train release gets bug fixes from a particular mainline release. has a number enclosed in parentheses (see Figure 3).

S. Rebuilds are a Cisco IOS vehicle that delivers fixes on an accelerated schedule.3.3 Rebuild Releases Circumstances and business demands may require that a number of images from a Cisco IOS train be rebuilt and posted prior to the next planned maintenance release. Figure 6: Example of a Rebuild Release Name—Mainline Train 3.2(8)T1.2(1a). indicates a rebuild of a maintenance release on a B. indicates a rebuild of a maintenance release on a mainline train (see Figure 6). Cisco IOS releases achieve GD status after meeting strict standards. defect resolution commits only ♦ No open Critical Account Program (CAP) issues ♦ Defect density measurements ♦ Software Reliability Engineering (SRE) projected defects ♦ Minimal code changes No serious defects in previous maintenance releases • Customer Success ♦ Extensive customer exposure ♦ High level of customer satisfaction Cisco IOS Reference Guide . T.1 Rebuild Release Naming A numeric suffix in a release name.1 General Deployment (GD) Release Criteria A GD release must meet the following criteria: • Improving Trend in Defect Backlog ♦ Customer Advocacy (CA) evaluation of known defects ♦ No new features or platforms.4 General Deployment (GD) Releases A Cisco IOS Software release reaches GD certification when its quality has been demonstrated by extensive deployment in diverse networks over extended periods of time. or E train (see Figure 5).3.4. such as 12. 3. such as 12. 3. Figure 5: Example of a Rebuild Release Name—T Train A lowercase alphabetic suffix in a release name.

3. The second letter can be a sequential revision identifier. when a release is declared GD. The early field adoption of new features and platforms that Cisco introduces in special releases benefits customers who need to run new network equipment or services. including bug fixes. A−Z. Y. Table 3: Special Release Technology Identifiers Identifier Target Technology or Platform X Y Varies. Special release names do not conform to a strict naming convention. Consequently.4.• Cisco Deployment ♦ Comprehensive system test and deployment in Cisco's internal network • Documentation ♦ Release Notes Enclosures (RNEs) complete 3.1 ATM/LAN Switching/Layer 3 Switching Naming of Special Releases The names of special releases have double letter identifiers after the train and maintenance release numbers. or Z. one time release Z A Aggregation/Access Server/Dial D xDSL H SDH/SONET J Aironet Wireless Networking M Mobile Wireless W 3. Figure 7 shows an example of a special release name. 12. When this type of naming is used.2(2)XB. the first letter of the double letter identifier can represent the one−time release X.5. The following table lists technology identifiers used in the names of special releases.2 General Deployment (GD) Lifecycle After a release attains GD status. is strictly limited and controlled by a program manager to prevent bugs from being introduced into the release. every subsequent revision of the release is also GD. Figure 7: Release Name Example 1 Cisco IOS Reference Guide . modification of the code.5 Special Releases A special release is a branch from a train code base that is introduced to quickly meet market demands for new features or additional platform support. While in this phase. it enters a restricted maintenance phase.

When this type of naming is used. Figure 10: Integration of Special Release Features into Parent Cisco IOS Reference Guide . 12. a special release is integrated back into the parent train (see Figure 10). Figure 8: Release Name Example 2 Figure 9 shows an example of another type of special release name.2(2)JA. Y. The second letter is a sequential revision identifier A−Z. 12.5. The second letter represents the one−time release X. The first letter of the double letter identifier indicates the technology the release delivers (see Table 3). or Z. 3.Figure 8 shows an example of another type of special release name. the first letter of the double letter identifier designates the parent of the special release. Figure 9: Release Name Example 3 Maintenance or rebuild identifiers (not shown in Figures 7−9) follow the double letter special release designator.2 Feature Migration of Special Releases At some point in its lifecycle.2(2)EX.

3 Packaging is initially available for Release 12.0 Cisco IOS Feature Sets A feature set is a bundle of the features available for a release. 4. Customers can use multiple feature sets of a release.3 Packaging simplifies the feature set selection process by consolidating the number of packages and using consistent package names across all platforms. Figure 11: Example of an Interim Build Name 4.3 Lifecycle of Special Releases Cisco’s end of life (EoL) policy is not applicable to special releases.3 for the Cisco 1700.6 Interim Builds An interim build is software from an internal Cisco engineering build process that the Cisco Technical Assistance Center (TAC) gives customers to use on a temporary basis to address a specific issue.6.5.3 Packaging introduces eight new feature sets (see Figure 12). 3. Figure 12: Cisco IOS 12. Cisco IOS Packaging Cisco IOS 12.1 Interim Build Naming An interim build name. and 3700 series routers. such as 12. Cisco IOS 12. Cisco IOS 12. 3. Other hardware platforms will be introduced with Release 12.1) has a train number plus a maintenance release number and decimal number in parentheses (see Figure 11). 2600.3. Customers who have an interim build installed on their network should contact TAC for assistance in replacing the interim build.3 Packaging Feature Sets Cisco IOS Reference Guide . Along with Cisco IOS legacy images.2(3.3T.1.

and the area of memory used by the image at run time.3(2)T release with the Enterprise Base feature set for the Cisco 3725 platform. the package feature content of the image. feature set. representing supported platform and feature set combinations. The following example shows the image name of a 12. 5. and other information about the image file.0 Cisco IOS Images A Cisco IOS image is a binary executable file of a feature set for a specific platform. Multiple images exist for a release. 5. Figure 13: Example of an Image Name Refer to the Cisco IOS Software Image Naming Convention for information about identifying the platform or board for which the binary software is built.1 Image Naming The software image name represents the platform.5. format. Cisco IOS Reference Guide .2 Images Running on a Router The show version command displays the name of the Cisco IOS image that is running on a device.

and compares releases. Often. no action is required by the customer. The roadmap shows the lineage of releases. • Deferral AdvisoryCisco issues a deferral advisory to announce the removal of a Cisco IOS image from Cisco's offerings and to introduce a replacement image. Critical communications about releases from Cisco that do require action include: • Security AdvisoryProduct Security Incident Response Team (PSIRT) issues a security advisory to alert customers to security issues that directly impact Cisco products and to help customers repair the Cisco product. Feature Navigator Finds releases that support a set of software features and platforms.0 Tools and Resources The Cisco IOS toolbox is a table that briefly describes and lists links to important Cisco IOS tools and documentation. software advisories describe problems with Cisco IOS Software that are platform specific or occur under unusual circumstances. do not affect most customers. • Security NoticesCisco issues Security Notices about issues that require a response to information posted to a public forum.2 Cisco IOS Roadmap The Cisco IOS roadmap consists of graphical links to detailed information about specific Cisco IOS releases and trains. and keywords. All rights reserved. customers are strongly urged to migrate from the affected image to the replacement image. 6. and finds out which software release supports a given hardware device. matches IOS and CatOS features to releases.1 Tools The following table briefly describes some of the most useful tools in the Cisco IOS toolbox. A deferral advisory is most often issued to correct a defect. All contents are Copyright © 1992−−2003 Cisco Systems Inc. Software Advisor Compares IOS releases. 6. and images. Table 4: Key Cisco IOS Tools Tool Description Software Selector Finds required features for a given technology. and downloads images of Cisco IOS Software. At the time that the deferral of a Cisco IOS image is advised. feature sets. or to make recommendations to mitigate general problems affecting network stability.0 Important Communcations about Releases Cisco issues many software advisories to customers for informational purposes only. and feature set. Bug Toolkit Searches for known bugs based on software version. feature set. release. and therefore. 7. Important Notices and Privacy Statement. Cisco IOS Reference Guide . platforms.6. Often. Cisco IOS Upgrade Planner Finds releases by platform. Customers can use the tools to get information about releases.