i use RB960PGS and power the device via PoE. I use a Ubiquiti PoE-Adapter wich was powering an 5AC Rocket before with Gigabit connection on LAN. After connecting the RB960PGS the interface came up with 100M only... How can i use Gigabit-Speed with RB960PGS with PoE-IN used?
Replace the UBNT PoE with an RB-GPoE or equivalent Gigabit PoE injector.
"Passive PoE" uses four of the eight wires for power. A simple passive PoE injector (without active electronics) simply disconnects those wires from the data pins and connects them to power, leaving only four wires for data. That's fine for 10/100, but Gigabit Ethernet requires that all eight wires carry data.
So, a Gigabit "Passive PoE" injector requires active electronics, to combine power and data on the same wires.