Hello,
Ruterboard RB500 series was buyed with RouterOS v.2.9.45 and afterwards was upgraded to v3.22. Is possible to upgrade to v3.33 now? Or is any limitation with upgrading to highest version?
Thanks for Your help.
http://wiki.mikrotik.com/wiki/All_about_licenses#Licenses_and_RouterOS_upgrades
You can upgrade to the latest v3, and depending on your license level also to v4RC1 (or v4 once it goes stable).