NW-31456-9 fix for PS4 error code
There’s a couple of ways to fix Sony’s NW-31456-9 PS4 error code that many of Down Today readers are seeing right now, although you should be aware this is due to changes Sony made with the PlayStation Network servers to help prevent DDOS attacks in the future.
We mentioned PSN sign-in problems on PS4 earlier and that a change to your MTU settings could be the easiest way to fix this issue. If that didn’t do it, then a more involved NW-31456-9 fix for this PS4 error code might be needed.
You can see the said error in the PlayStation 4 screenshot above, which in this situation came with the “can’t connect to the server within the time limit” message.
The solution isn’t a guarantee for success and some gamers might want to wait for Sony to offer their own fix. The current stance is to just reboot the console, or change MTU settings unofficially, but see the fix for this PS4 NW-31456-9 error below and of course make these changes at your own risk.
You’d need to open a special Port in your router for the PlayStation console. This involves first going to the router IP address in a web browser, then logging into your router via that page.
Each home network setup is different and depends on brand, but find the Advanced Menu and select Firewall Settings. You need to enable the DMZ Host with your PS4’s IP Address, although you might want to make this static if possible and of course remember to click save.
To connect to the internet manually though your PS4, change the network settings to a Default Gateway and Subnet Mask the same as your internet details on the router, or via looking at information when connected to WiFi on a computer. Make sure the IP address is set for your PS4, and the any DNS you know for primary and secondary DNS. Google’s 220.127.116.11 and 18.104.22.168 DNS address is good for this setting.
As you can see above, you will need some knowledge of networking to make these changes. We’d recommend you try changing the PS4 MTU settings to 1450, or 1472, first before trying the networking changes. If this works for you, or even if you still have problems then leave a status update on this page.