Can't connect to PSN with new PS4, error nw-31456-9

Hi all, I just bought a PS4 to upgrade from my PS3. The latter has no issues connecting to PSN, either via wifi or ethernet while the former gives me the dreaded NW-31456-9 error, again, both on wifi and ethernet. All googling I have done seems to point me towards changing the parameters of my router, but I am unclear whether this is relevant given that 1) my PS3 has no issue connecting to PSN 2) my PS4 can't connect even with a wired connection

Thoughts and suggestions would be much appreciated

Cheers