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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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1 6. see Cisco IOS Software Technical Documentation.1 1.1 3.4 3. implementing.3 3.2 7.2 3.2 Image Naming Images Running on a Router 6. This document describes the release model—trains. and managing network infrastructures.3 3.1 5. and images. releases.3 Packaging 5.0 Cisco IOS Images 5.0 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.0 Introduction 1.5 4. designing.2 2.0 2.1 2.0 4. For information about how to install or configure Cisco IOS Software.0 6.2 Growth of Cisco IOS Scope of this Document 2.1 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 3. feature sets. 1.

such as Feature Navigator and Upgrade Planner • The Cisco IOS roadmap 2. and an array of hardware that ensures its longevity. 1. 1. storage networking. To perform these critical tasks. hundreds of new applications.2 Scope of this Document This document is intended for network administrators who upgrade and maintain a network. From the beginning. optical. Today. Cisco IOS Software is the unifying thread that connects otherwise disparate networks to build a scalable network infrastructure. and network services to support e−commerce conducted over multi−service (Data/Voice/Video) applications. minimizing costs. Cisco IOS Software supports new areas of networking technology. As the router market exploded. maximizing ROI. wireless. such as voice and video over IP networks. It enables network services and Internet applications. with the addition of thousands of new features. serving as an end−to−end solution for global networking. network administrators must understand the following topics: • Feature sets and images • Cisco IOS tools. Customers can leverage their investment in Cisco hardware and software solutions for years. so did Cisco’s growth. Cisco IOS Software diversified from one train of releases to multiple trains supporting different feature sets for different customer needs.• Software Center: Cisco IOS Software • Cisco IOS Upgrade Planner • Cisco Feature Navigator • What's New for Cisco IOS Software 1. and a wide array of platforms. Cisco IOS Reference Guide . 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.0 Cisco IOS Trains A Cisco IOS train is a vehicle for delivering releases that evolve from a common code base. In recent years. and ensuring investment protection. applications.1 Growth of Cisco IOS The Internet was a driving force in Cisco’s growth.0 Introduction Cisco IOS Software is network system software that tightly integrates a broad range of Internet and enterprise network hardware. Cisco routers ran Cisco IOS Software. Cisco IOS Software supports an unparalleled array of features. Cisco IOS Software evolved over time and met the challenge of rapid changes in the business and network environment in the last decade.

12.2.2T (see Figure 1). such as 12. T Introduces new features and fixes defects. and fixes defects. and fixes defects.0S. 2.3T S Consolidates 12.1T.2S E Targets enterprise core and SP edge. are parents of other trains. and does not add 12. 12. voice.2. 12.2 mainline.3B 2.0S. Cisco could introduce new features in a Cisco IOS release from one train without affecting the code base of the other train. 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. 12. such as 12.1E. Mainline trains.2. 12. 12.2 Mainline and T Train Relationship Early in Ciscos history. and 12. which supports high−end backbone routing. 12.2. Inherits features from the parent T train. are built from previous generation T trains. supports advanced QoS.2.1 T Train and Mainline Evolution Mainline trains.1E B Supports broadband features and fixes defects. security. 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. and firewall. such as 12.2B. Figure 1: Evolution of T and Mainline Trains Cisco IOS Reference Guide .1 Types of Trains Today.3 additional features. 12. such as 12.

Cisco informs customers that a train has reached one of these milestones by issuing product bulletins and other communications.2. 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.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). maintaining.3 Train Lifecycle Milestones At some point in the life of a train. Table 2: Milestones in the Life of a Train Milestone Available through Sales Channels Bug Fixes TAC Support Download from Cisco. New features are integrated into the T train onlythe mainline train receives bug fixes only. Each new release receives regular maintenance during the early part of the life cycle.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. Cisco IOS Reference Guide . Cisco stops selling. Figure 2: Bug Synchronizing and Feature Integration 2.2. and supporting it.

Figure 3: Example of Maintenance Release Name 3. depending on the train.1. Types of Releases • Maintenance releases • Rebuild releases • General Deployment (GD) releases • Special releases 3. Figure 4: Maintenance Release Number Sharing Between Mainline. T. T.2 Cisco IOS Maintenance Release Revision Number Sharing Bug fixes are synchronized from the mainline to the T train (see Figure 2). 3. Maintenance releases typically occur every eight to thirteen weeks. or both.2(3)T. so customers can determine which T and S train release gets bug fixes from a particular mainline release.2.2. has a number enclosed in parentheses (see Figure 3). Cisco started sharing a sequence of numbers among maintenance releases on the mainline.2 Maintenance Releases A maintenance release is a scheduled revision of Cisco IOS Software that introduces new features or bug fixes.2 mainline train.0 Cisco IOS Releases A release is a snapshot in time of the code base of a train. 3. such as 12.3. and S trains (see Figure 4). and S Trains Cisco IOS Reference Guide .1 Maintenance Release Naming A maintenance release name. With the release of the 12.

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.4. Figure 6: Example of a Rebuild Release Name—Mainline Train 3.2(1a). S. Rebuilds are a Cisco IOS vehicle that delivers fixes on an accelerated schedule. 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 . 3. indicates a rebuild of a maintenance release on a B.3.1 Rebuild Release Naming A numeric suffix in a release name.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. 3.1 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. or E train (see Figure 5). such as 12. such as 12.3. indicates a rebuild of a maintenance release on a mainline train (see Figure 6). Figure 5: Example of a Rebuild Release Name—T Train A lowercase alphabetic suffix in a release name.2(8)T1. T. Cisco IOS releases achieve GD status after meeting strict standards.

Consequently. 12.2(2)XB. or Z. Y.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.2 General Deployment (GD) Lifecycle After a release attains GD status. when a release is declared GD. While in this phase. modification of the code. When this type of naming is used. Table 3: Special Release Technology Identifiers Identifier Target Technology or Platform X Y Varies. including bug fixes. every subsequent revision of the release is also GD. Figure 7 shows an example of a special release name. The following table lists technology identifiers used in the names of special releases. is strictly limited and controlled by a program manager to prevent bugs from being introduced into the release. A−Z.4. The second letter can be a sequential revision identifier. 3. one time release Z A Aggregation/Access Server/Dial D xDSL H SDH/SONET J Aironet Wireless Networking M Mobile Wireless W 3. the first letter of the double letter identifier can represent the one−time release X.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. Special release names do not conform to a strict naming convention.• Cisco Deployment ♦ Comprehensive system test and deployment in Cisco's internal network • Documentation ♦ Release Notes Enclosures (RNEs) complete 3. 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. it enters a restricted maintenance phase. Figure 7: Release Name Example 1 Cisco IOS Reference Guide .5.

the first letter of the double letter identifier designates the parent of the special release.2(2)EX. 12. Figure 8: Release Name Example 2 Figure 9 shows an example of another type of special release name.Figure 8 shows an example of another type of special release name. a special release is integrated back into the parent train (see Figure 10). Figure 10: Integration of Special Release Features into Parent Cisco IOS Reference Guide . or Z. Figure 9: Release Name Example 3 Maintenance or rebuild identifiers (not shown in Figures 7−9) follow the double letter special release designator. When this type of naming is used. 3.2(2)JA. The second letter is a sequential revision identifier A−Z. 12.2 Feature Migration of Special Releases At some point in its lifecycle. Y.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).

3 for the Cisco 1700. and 3700 series routers. Other hardware platforms will be introduced with Release 12.5. Cisco IOS 12. Customers can use multiple feature sets of a release. Figure 12: Cisco IOS 12.3 Packaging Feature Sets Cisco IOS Reference Guide . Cisco IOS Packaging Cisco IOS 12. 4. Figure 11: Example of an Interim Build Name 4.6.1 Interim Build Naming An interim build name.3.2(3. such as 12.1.3 Packaging introduces eight new feature sets (see Figure 12). 3.6 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.3T.3 Packaging simplifies the feature set selection process by consolidating the number of packages and using consistent package names across all platforms.0 Cisco IOS Feature Sets A feature set is a bundle of the features available for a release. Cisco IOS 12.3 Packaging is initially available for Release 12. Along with Cisco IOS legacy images.3 Lifecycle of Special Releases Cisco’s end of life (EoL) policy is not applicable to special releases. 3. Customers who have an interim build installed on their network should contact TAC for assistance in replacing the interim build.1) has a train number plus a maintenance release number and decimal number in parentheses (see Figure 11). 2600.

5. and the area of memory used by the image at run time. feature set. Cisco IOS Reference Guide . The following example shows the image name of a 12. the package feature content of the image. Multiple images exist for a release. 5.0 Cisco IOS Images A Cisco IOS image is a binary executable file of a feature set for a specific platform.1 Image Naming The software image name represents the platform. 5. representing supported platform and feature set combinations.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 other information about the image file.3(2)T release with the Enterprise Base feature set for the Cisco 3725 platform. 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. format.

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. Important Notices and Privacy Statement. release. Table 4: Key Cisco IOS Tools Tool Description Software Selector Finds required features for a given technology. Software Advisor Compares IOS releases. Bug Toolkit Searches for known bugs based on software version. All rights reserved. and feature set. • 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. software advisories describe problems with Cisco IOS Software that are platform specific or occur under unusual circumstances. Often. Feature Navigator Finds releases that support a set of software features and platforms. feature set. and keywords. 6. 6. or to make recommendations to mitigate general problems affecting network stability.0 Tools and Resources The Cisco IOS toolbox is a table that briefly describes and lists links to important Cisco IOS tools and documentation. • 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. 7. The roadmap shows the lineage of releases. do not affect most customers. At the time that the deferral of a Cisco IOS image is advised. and downloads images of Cisco IOS Software. platforms. and compares releases. Customers can use the tools to get information about releases. and therefore. matches IOS and CatOS features to releases. no action is required by the customer. 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. Cisco IOS Upgrade Planner Finds releases by platform.0 Important Communcations about Releases Cisco issues many software advisories to customers for informational purposes only. customers are strongly urged to migrate from the affected image to the replacement image. Cisco IOS Reference Guide . feature sets. and finds out which software release supports a given hardware device. Often. All contents are Copyright © 1992−−2003 Cisco Systems Inc.6. and images.