How to access a subnet from the outside?

Question

Network administration

Good afternoon!
We rent a room, the Internet from the owners is organized as follows:
TP-Link router, white IP -> tenant routers
Specifically, our office uses ASUS RT-N10U with DD-WRT firmware.
Total: TP-Link router, white IP -> ASUS RT-N10U -> server
How to get access (RDP at least) from the outside to the server if it is not possible to forward ports or make any settings on TP-Link?
Thank you.

Answer 1

Let your server initiate any VPN connection to the outside at startup.

Answer 2

If only RDP - use teamviewer.
If you decide to use a VPN, use OpenVPN.
ps no ads, just easy to set up tools

Answer 3

Outside, set up a VPN server on a white IP (for example, on a purchased VPS). Large capacities are not needed there, so the cheapest tariffs are enough. Exposing RDP to the outside in its pure form (by port mapping, for example) is unsafe.