Maximum Transmission Unit (MTU)

Maximum Transmission Unit, or MTU, defines the maximum size of a data unit that can be transmitted across a network interface or network segment. For Ethernet, the standard IP MTU is typically 1,500 bytes. Larger values can be used with technologies such as Jumbo Frames. If an IP packet exceeds the permitted MTU, it may need to be fragmented or retransmitted at an appropriate size, depending on the Internet Protocol version and network configuration. Inconsistent MTU values along a network path can cause packet loss, connectivity issues or reduced performance. Mechanisms such as Path MTU Discovery help determine the maximum usable packet size for a transmission path. Correct MTU configuration is therefore important for reliable and efficient data transmission across local networks, WAN connections and VPN infrastructures.