This Christmas (2014), several gaming networks were attacked by a DDoS. One of those networks being the Playstation Network (PSN). This resulted in severe downtime during the holiday season. Sony is/was working hard to resolve this and service is being restored all around the world. Except for me (and probably several thousand other gamers). As of this morning (December 29th, 2014) I was unable to log on to PSN. All I got was one of the much telling error codes:
NW-31456-9
CE-33987-0
Someone on the Interwebs mentioned that a change in the MTU size might help. The MTU size is the maximum transfer unit on a network, which is normally at 1500 (bytes) for regular network clients. In some case it's preferable to adjust this size (I won't get into details).
In the case of PSN being down, an adjustment from 1500 (the default) to 1473 seems to do the trick at the moment. Not sure if it wil hold up in the (near) future, but at least you can get online to play on your new Playstation 4 or with the new game you got for Christmas.
- Go to the “Settings” menu.
- Go to “Network” sub-menu.
- Go to "Set Up Internet Connection".
- Choose your media (WiFi or LAN).
- Choose “Custom.”
- Leave everything as default except MTU (Manual).
- Change MTU settings to “1473”.
- Save your changes.
- Test the Internet connection.
And if you are more of a visual kinda person:
Everything should work now. If not, you may try a reboot.
Lowering the MTU size means that smaller packets are being send over the network (max. 1473 bytes instead of 1500 byte packets) , this is not a bad thing, but might lead to some performance problems in some cases. Just remember that you changed this setting. You want to (or have to) change this back to the default (1500) in the future.
I do not know if this works for other gaming devices. You may try at your own risk (and leave the results in the comments if you'd like).
UPDATE: As of this morning I was able to sign in to PSN with an MTU of 1500 (access the Playstation Store etc.), but I was unable to play online games (Battlefield 4). Changing the MTU back to 1473 fixed that (again).
UPDATE 2: As of this morning (31 december) I can also connect to PSN with an MTU of 1500, so everything is back to normal.