How To Enable Jumbo Frames In Linux - LinuxConfig.org

Are file transfers slow on your network? Are you constantly passing data between your computers? Well, maybe jumbo frames are for you. Jumbo frames are larger than standard network packet payloads. Normally the payload size or MTU(Maximum Transfer Unit) is set to 1500 bytes. Jumbo frames can support to 9000 bytes per packet.
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-enable-jumbo-frames-in-linux

Schism

Although large MTUs are nice, devices with smaller MTUs will not “break them up into smaller sizes as needed” without a gateway that bridges the exact MTU sizes on either side (i.e. a 1500 byte MTU interface and a 9000 byte MTU interface). You can get away with this if all of your packets are small, like SSH but if you try to send a 1501 byte MTU packet to an interface with a 1500 byte MTU the interface will just drop the packet as corrupt.

Bruce Ferrell -> Schism

Actually it depends on the DF bit in the header and a thing called “path mtu discovery”. IF DF is set, you’re correct. If it is not, you are incorrect.

EDA -> Bruce Ferrell

Bruce Ferrell
– haven’t played with frame setting for years. Question: how would one force / set the DF in the header (if such is possible).