How to upgrade C800 Software to least version

[eng_adel273]

Cisco IOS Software, C800 Software (C800-UNIVERSALK9-M), Version 15.2(4)M4, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2013 by Cisco Systems, Inc.
Compiled Thu 20-Jun-13 16:14 by prod_rel_team

ROM: System Bootstrap, Version 15.1(4r)M, RELEASE SOFTWARE (fc1)

AamalNet uptime is 38 weeks, 6 days, 5 hours, 16 minutes
System returned to ROM by power-on
System image file is "flash:c800-universalk9-mz.SPA.152-4.M4.bin"
Last reload type: Normal Reload
Last reload reason: power-on

[Leo Laohoo]

Did anyone attempt to read the Release Notes?

[Karsten Iwen]

As Leo mentioned, there are release-notes for that. In addition to that:

1. You need a maintenance-contract to load the newest image. Without that, you only get security-bugfixes for your running release.
2. For the newest IOS, you need a certain amount of RAM that your router might not have out of the box. Check that before going further.

[eng_adel273]

thanks for your support .

I don't have contract , how get & apply security-bugfixes for running release.

[Karsten Iwen]

Go to https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190925-identd-dos and read through the section "Fixed Software".