PPSSPP wired LAN in Linux

[Abbanon]

It might be the type of cable you have.
A simple, basic Ethernet cable used for an internet connection between router/modem and computer won't work for computer-to-computer connection.
It takes a special kind of two-way Ethernet-like cable, that's made specifically for computer-to-computer/LAN connectivity.

However, if the cable you're using is actually made for LAN...
I'm sure there's an extra step needed, such as using the local IP in the "PRO Adhoc server IP address" option on all PPSSPP instances being used.

But I can't 100% confirm the exact steps needed for local LAN, seeing as I don't have a proper LAN cable to test it for myself yet.
I've only had experience with using Hamachi, and it works out fine for me. I'm sure someone else may have the proper answer, and know of the correct steps needed.
The most I can do is try to help with troubleshooting.