I spoke to a customer recently who was concerned about their Red Hat Enterprise Linux 2.1 server and its Red Hat support status. After some digging, I found these items on Red Hat's security site:
Red Hat Enterprise Linux (version 5)
End of Full Support: Mar 31, 2010
End of Maintenance Support: Mar 31, 2014
Red Hat Enterprise Linux (version 4)
End of Full Support: May 15, 2008
End of Maintenance Phase: Feb 29, 2012
Red Hat Enterprise Linux (version 3)
Full Support (including hardware updates): April 30, 2006
Maintenance Support: Oct 31, 2010
Red Hat Enterprise Linux (version 2.1)
Full Support (including hardware updates): Nov 30, 2004
Maintenance Support: May 31, 2009
Here's the difference between the levels of support:
Full Support
Start Date: General Availability
End Date: 3 Years from General Availability date
Description: During the Full Support phase, new hardware support will be provided at the discretion of Red Hat via Updates, Additionally, all available and qualified errata will be applied to the Enterprise products via Updates (or as required for Security level errata.) And finally, updated ISO images will only be provided during Phase 1: Full Support.Maintenance
Start Date: 3.5 years from General Availability (end of Deployment)
End Date: 7 years from General Availability
Description: During the Maintenance phase, only Security errata and select mission critical bug fixes will be released for the Enterprise products.
Data was gathered from http://www.redhat.com/security/updates/errata/
