Grant <emailgr...@gmail.com> wrote:
> 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.