I have 50 mikrotik routers.
50% of this routers have internet, but other routers don't have internet, only private network.
All routers have access to 1 IP address, ex. 192.168.111.1
I can create http-web server on this IP and leave file with firmware, ex. http://192.168.111.1/mikrotik

Script must check this web and if he find there firmware file with newest version than mikrotik router have he must download file and update firmware, if there is no new firmware script must check HW version and upgrade it if its needed.
I found this script and it work good, but he need internet access.
https://github.com/massimo-filippi/mikr ... pgrade.rsc

Thanks a lot for help!