King Size MTU 9000

Ethernet has taken over all networks. We use it at home, at work. But it’s also used in a data center, as 1G, 10G, 40G or even 100G to 400G. There is one thing where you could stand out and it is the MTU.

While almost all ISPs and users use a standard MTU of 1500, I’m slowly moving to using 9000 in my entire network.

I think it’s the supreme discipline in networking to transport big packets. It usually requires some work, on software (compatibility), hardware (configuration).

Nevertheless, I will try to move everything to MTU 9000, because it is well worth it. Transfers increase, switches have less to do, and also the network card on the PCI bus can relax easily at once.

With “tracepath” you can then track the path with the respective MTU under Linux/BSD, it should stay at 9000 as far as possible.