Exit node without advertising routes "seem" to work, but in reality no internet. Could it be because this is an armv5te based CPU? Maybe it's too old for tailscale?
tailscale up --advertise-exit-node
This looks like it's working, but no internet in reality. tailscale up --advertise-routes=192.168.1.0/24 --accept-routes --advertise-exit-node
This, it freezes. I would send the logs but it freezes, I reset the NAS and it still doesn't work. Only hard reset works, but then I have to set up everything again.
Btw, do I do anything about firewall? I simply passed about that part because this device doesn't have wan port or anything. The guide is for routers.
Ok it freezes again:
Ok it worked. I don't know why. This time no freeze. But I actually created a tailscale interface this time. And did the firewall related stuff at wiki, but only selected LAN at last two selection, you know since WAN will be empty for this NAS device. See here:
Your setup is not one that I have dealt with before.
I have setup routers to act as Exit Nodes and placed them at sites in a Double NAT with nothing connected to the LAN side of the Exit Node Router. In that situation it is WAN port that is communicating to the Tailnet and I would think it would be the same for you as the NAS has been turned into a Router, thus the NAS LAN port is now the NAS/Router WAN port.