Hi Team.
I have 8 year old RB751U-2Hnd.
I bought his successor, the RB951G-2Hnd.
Now I want to equip a new device with a copy of the configuration of the old device so that it would just reposition the power and all 5 UTP cables and the new device should work.
Is this possible?
How?
Is there a procedure for how this is done?
HOWTO?
Thank you very much in advance 
All the best in 2020,
robi
It is not possible to do it using binary backup/restore procedure. Don’t even try, the new unit will become a brick while you say cheese … (not permanently, you can get it back, but you’ll just loose time).
You could do it by using ASCII export from old box, edit config to match the new hardware, reset the new unit to no defaults and apply the modified export from the old unit. Beware that ASCII export doesn’t export just everything, missing things are certificates, ssh keys, usernames and passwords (and possibly more).
However, I wouldn’t recommend any of these methods. I recommend to export old config to ASCII file (using CLI command /export fole=exported_config.rsc), then configure the new unit. However, I strongly suggest you to reconsider old configuration, specially firewall filter rules. The new defaults are pretty sane, so quite probably you only need to add a few minor details.