Understanding Cisco IOS Releases

Answered Question
Sep 17th, 2009
User Badges:

I've been reading about Cisco IOS releases from this site: http://www.cisco.com/warp/public/620/1.html


and it's so confusing! It there a simple way to understand what all the T, S, etc. means?

Correct Answer by pompeychimes about 7 years 7 months ago

It used to be even harder!


Check out Stretch's cheat sheet over on packetlife...

http://www.packetlife.net/static/cheatsheets/cisco-ios-versions.pdf

Correct Answer by Edison Ortiz about 7 years 7 months ago

Regular IOS routers would use the 12.4M (Mainline) or 12.4T (Technology). You will find the T train to contain the newest features but it may also contain the most bugs. We often recommend Mainline over T train if you are interested on stability in your network without the need of new features.


Other tracks would be platform specific, for instance;


12.2SX = Catalyst 6500

12.2SE = Catalyst 3xxx switches

12.2SR = Cisco 7600 Routers

12.2SB = Cisco 7200 and 7300 Routers.


There are a lot of tracks out there and I can understand your confusion but if you stick to the main ones, you should be ok.


Any track in particular you are looking for?


__


Edison.

Correct Answer by platinum_jem about 7 years 7 months ago

You can also refer to this for more info

http://www.cisco.com/en/US/products/sw/iosswrel/ps1818/products_tech_note09186a0080101cda.shtml


In general, the various IOS releases


T = Testing and training releases

ED = Early deployment

GD = General deployment


Normally T releases are the versions that were released for ad hoc bug fixes


ED are initial stages of deployment but still subjected to bugs.


GD are the most stable versions and can run for a long time before the next maintenance reboot.

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 5 (3 ratings)
Loading.
Correct Answer
platinum_jem Thu, 09/17/2009 - 19:10
User Badges:

You can also refer to this for more info

http://www.cisco.com/en/US/products/sw/iosswrel/ps1818/products_tech_note09186a0080101cda.shtml


In general, the various IOS releases


T = Testing and training releases

ED = Early deployment

GD = General deployment


Normally T releases are the versions that were released for ad hoc bug fixes


ED are initial stages of deployment but still subjected to bugs.


GD are the most stable versions and can run for a long time before the next maintenance reboot.

Correct Answer
Edison Ortiz Thu, 09/17/2009 - 19:14
User Badges:
  • Super Bronze, 10000 points or more
  • Hall of Fame,

    Founding Member

Regular IOS routers would use the 12.4M (Mainline) or 12.4T (Technology). You will find the T train to contain the newest features but it may also contain the most bugs. We often recommend Mainline over T train if you are interested on stability in your network without the need of new features.


Other tracks would be platform specific, for instance;


12.2SX = Catalyst 6500

12.2SE = Catalyst 3xxx switches

12.2SR = Cisco 7600 Routers

12.2SB = Cisco 7200 and 7300 Routers.


There are a lot of tracks out there and I can understand your confusion but if you stick to the main ones, you should be ok.


Any track in particular you are looking for?


__


Edison.

iyde Tue, 09/22/2009 - 12:55
User Badges:
  • Silver, 250 points or more

Well, that book is from the year 2000. Cisco has made changes a lot of times since then on the naming and numbering of IOS....

Stay with Edison's post; it's the most helpful.

HTH

Actions

This Discussion