NSO upgrade from M9 to latest possible ? : I have one of the NSO with 200K VPN services (L2 ; L3VPN) which we used it for testing previous COE2.0 release. It is on M9 (172.20.63.190; cnctest/Ovatest123@) version. Is it possible to upgrade it to latest current version without disturbing the existing VPN services ?  OR due to changes in current code, this is not possible ? Could you please suggest a better and recommended option here. 
Upgrade from CNC 2.0 M9 release to CNC 3.0 M5 release is not supported as there are backwards incompatible model changes from M9 to M13. There is an additional NBC change for L2NM from CNC 2.0 to 3.0 captured here (point 11): We recommend installation of M5 release to create services for 3.0 scale testing.Thanks for info !! So the real time customers on CNC 2.0 cannot migrate/upgrade to current latest release ? Even they need to go for fresh install ? What is the recommended plan for them ? Upgrade is supported for TSDN Core Function Pack. Please refer to our wiki for upgrade from 2.0 to 3.0.There was no requirement to support upgrade for sample function packs as they are customizable by CX and/or customers.