What is the maximum transmission unit (MTU) size typically used in Ethernet?

The maximum transmission unit (MTU) size that is typically used in Ethernet is 1500 bytes. This size is defined in the Ethernet standard and represents the maximum amount of data that can be transmitted in a single Ethernet frame. The 1500 bytes MTU is critical because it allows for efficient use of network resources and helps to prevent fragmentation, which can occur when packets exceed the MTU size.

Using a standard MTU size also simplifies network configuration and compatibility between devices from different manufacturers, ensuring efficient communication without the need for special adjustments. In Ethernet frames, this 1500 bytes MTU size includes the data payload, leaving space for the Ethernet header and trailer, which are essential for the operation of protocols like IP.

Higher MTU sizes, such as 9000 bytes (which corresponds to jumbo frames), are used in specific scenarios to improve performance, particularly in environments demanding high data throughput and reduced overhead, but they are not the typical size for standard Ethernet communication. Therefore, while other options may represent alternative configurations, the commonly accepted and widely used MTU size in Ethernet is indeed 1500 bytes.