>> > 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? >> >> AFAIK the MTU is defined for every network interface separately. For an >> ADSL connection it is common that a lower MTU is needed because of the >> PPPoE header information that is encapsulated in the ethernet frames. >> But in that case it is sufficient to lower the MTU just for the WAN >> interface that is connected to the DSL modem. >> If you don't use protocol encapsulation in your LAN then there should >> be IMHO no reason for lowering the MTU of your internal interfaces. >> >> -- >> Regards >> wabe > > MTU is per network interface but you really don't want to end up having > your router fragment every IP packet because systems on your subnet are > using a larger MTU. > > Todd
That makes sense. So in my case, I'm thinking 1492 MTU on every interface in the network. So I'm sure I understand, should everyone with a DSL connection set an MTU of 1492 (or potentially lower) on all of their network interfaces to avoid packet fragmentation? - Grant
