f13.net

I messed around with my routers MTU a couple days back and it pissed off my 360 enough that it refused to connect to LIVE. So, I reset the setting back to 1500 and now my 360 insists on dropping me from LIVE every 10 minutes or so. I've gone over the settings in the router numerous times and can't figure out why it would be doing what it's doing. I don't see any options in the 360 that are associated with MTU or anything like that. The router is a WBR-1310 and Google brings up nothing about it booting people from live.

You made the MTU bigger then smaller again?  Maybe you have to reinitialize everything?  I don't know what might be messed up but it does sound like you could be having an oversized packet problem.

The default MTU size is 1500. I lowered it to 1300 initially and returned it to 1500.

Can I ask why you lowered the MTU size?  Just curious as to why 1300, I've heard 1488 and 1492 bandied about before but 1300 is a new one on me.

Also, reset button on the back of the router.  Stick a pencil in there and Bob's your uncle.

I was dicking around and heard "Change the MTU" to resolve a lag issue I've been having. Wasn't given a number, so went with that.

I'll try the factory reset and see what happens.

General note: I'd stay away from recommendations like that, simply because they are recommending a broad change to a fundamental aspect of your networking to fix a single application's issue.

MTU honestly is not nearly the big deal it used to be, but highly tuned networking environments can be very susceptable to what appear to be very small changes. Torque's networking for example is tuned for a very oldschool value of 500, but if you went in and changed it manually to 300 on your router (and this in actuality forced your packets to be broken up to fit the MTU, which isn't always the case), you'd get some extremely unexpected, and probably hugely distracting lag issues as a result in some cases.

If you are running a customer firmware router running linux a lot of the assumptions made in the earlier 2.6.x kernels played havoc with the TCP settings under certain conditions (window size/window scaling come to mind).   If it's just something off the shelf you can probably ignore this and go update the firmware from the vendor just to be safe.

To echo other statements: there shouldn't be much of a need to muck with the default MTU on your router unless you have an archaic method of connecting to the inatarwebs.