A while back I was having networking issues. I eventually tried drastically lowering the MTU of all the systems onsite and the issues disappeared. I always thought the issue was due to the MTU on our modem/router. Today I read that AT&T DSL requires a 1492 MTU so I increased the MTU of our systems up to 1492 and haven't had any issues. Do certain ISPs require you to change the MTU of your entire network, or is this likely due to our AT&T modem/router itself?