I'm trying to debug Flutter apps with ADB over TCP, so tried the following (Android connected with USB) according to this:
adb tcpip 5555
adb connect <Android-ip-address>:5555
But I always get unable to connect to <Android-ip-address>:5555: No route to host.
I installed the plugin Android WiFi ADB to Android Studio, but...no hope.
After that, I tried to ping my Android phone from PC with that command ping <Android-ip-address>, but again it failed with that output From <PC-ip-address> icmp_seq=1 Destination Host Unreachable.
Now I tried to do the same thing (PC & phone), however on an another router (Tenda) and it worked like a charm.
So the problem is from my router, which is a D-Link with a firmware version ME_1.03. I searched for "Port Forwarding" and stuff like that, but I don't know what I'm doing and I didn't come up with any result.
What can I do to solve it.
Finally I found it. It's because of a feature (as others said) called WIFI/User Isolation in routers. But in my case, it's called Relay Blocking. Anyway, you have to disable it.
In D-Link (DSL-2740U) - Firmware Version ME_1.03:
Main Page ---> Advanced ---> Advanced Wireless Settings ---> Relay Blocking. Check disabled choice.