I didn't jump on the 15.3 train yet as that is too new and these new versions have too many "challenges". If you don't need any new functions, the most stable version is probably 15.1.4M7 or 15.2.4M5. If you want to stay on 15.3, then 15.3.1T3 is the newest update to your running version.
Why do you want to upgrade the IOS on the router? If everything is working ok, dont break it by upgrading it to anither software. If I dont have any specific hardware or software requirements, I would not upgrade the router's IOS. Is there anything specific you are looking for?
As such there is no software and hardware requirement. But we arre using GETVPN in our network and there is some addition in the timers in15.3(2)Tversion. But this version is very new, launched in Dec 13.
So finally I decided not to go with the updated version, as such we not facing any problem with runn version.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...