Annoyingly, the RB5009 doesn’t have a voltage regulator on its PoE-out ports. So it outputs ~48V, but other Mikrotik devices that support PoE-in only support ranges like 20-34V.

There is a solution! And I wanted to share it with you guys as my first post :)

48V-to-24V in-line convertor: https://www.aliexpress.com/w/wholesale-poe-Converter-48V-to-24V.html

This will convert the output from the RB5009 to 24V. Tested with PoE-out on RB5009UPr+S+ and PoE-in on CSS106-5G-1S.

The RB5009 is a fantastic device.