Cisco IOS version 15.0
Cisco has announced a major change in the IOS versions, from the latest version 12.4 up to version 15.0
This is a major change and introduces some key changes, particularly to the way in which additional features are now “activated” using a licence key.
The version 15 train also introduces a more “simplified” version numbering system: (see this post for the previous IOS numbering system)
Support Lifecycle and Milestones for Cisco IOS Software Release 15.0(1)M
Key highlights of Release 15 M and T, illustrated in Figure 1 below, include the following:
• Feature inheritance from Cisco IOS Software Releases 12.4T and 12.4 Mainline*
• M (extended maintenance) releases every 20 months – allows customers to qualify/deploy/remain on releases longer with active bug fix support.
• Standard maintenance 15 T releases ideal for very latest features and hardware support before the next M release becomes available on Cisco.com (the first 15 T release is planned for 2nd quarter calendar year 2010).
• Rebuilds of Release 15 M and T releases contain bug fixes and ongoing maintenance.