Maximum Transmission Unit (MTU) is the size of the largest packet that can be sent over a network. The size of the MTU determines the amount of data that can be transmitted.
If a packet is larger than the MTU allowed by the frame, the device fragments the IP packet into multiple parts that fit into frames, and sends the parts of the fragmented IP packet separately, in different frames. The device that receives the multiple fragments of the IP packet reassembles the fragments into the original packet. The packet fragmentation can be reduced by increasing the MTU.
Extreme 9920 supports jumbo packets of 9216 bytes, which is the default, and you can change the MTU for individual IP interfaces. The valid range is 1024-9216. The global MTU applies to all interfaces. The interface MTU configuration overrides global MTU configuration.