Fix PSN temporarily with MTU change on the PS4
There are still many users who cannot sign into the PlayStation Network as of today, despite Sony’s claim that it’s up and running again. Apparently, while services resume, they are still not available to everyone, as many of you are still getting the NW-31194-8 error (or in some cases, even CE-35287-5) but there is a temporary fix.
According to Sony, you can change the MTU settings on the PlayStation 4 to help you get back on PSN while the service gradually returns.
To change the MTU settings follow these steps:
You may have to reset the PS4 after that but many users on Twitter and the PlayStation forums are getting results with those steps, so give it a go.
Once PSN is back in full form though, you’ll need to go back and change the MTU back to 1500.