1500 Bytes
The standard Maximum Transmission Unit (MTU) used in networks is 1500 bytes. Learn why and an interesting alternative: Jumbo Frames.
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Maximum Transmission Unit
The standard Maximum Transmission Unit (MTU) used in networks is 1500 bytes. This means that, typically, the largest amount of data that can be sent in a single network packet without fragmentation is 1500 bytes. The 1500-byte MTU was chosen as the standard for networks in the early days of networking because it offered a good balance between efficiency and compatibility. You can check the MTU of a network interface by running the following command:
ip link show venet0
2: venet0: <BROADCAST,POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN mode DEFAULT group default
link/void
INFO: venet0 is a virtual network interface commonly used in OpenVZ container-based virtualization. Here, it has a maximum transmission unit of 1500 bytes, the standard.
Jumbo Frames
However, there is another form of network packet called a Jumbo frame, a network packet with a size larger than the standard 1500-byte MTU. Typically, Jumbo Frames have an MTU of 9000 bytes, though they can be configured anywhere between 1500 and 9000 bytes. Jumbo packets are sometimes used as fewer packets are needed to transmit the same amount of data, which can lead to improved network performance in certain cases.
- Reduces Network Overhead - Fewer packets mean fewer headers, reducing processing time.
- Lowers CPU Utilization - The server and network devices process fewer packets.
- Improves Throughput - Especially beneficial for high-speed 10GbE+ networks, data centers, and storage systems.
Jumbo Frame Problems
However, don't go rushing to increase the MTU of your network devices as Jumbo frames are not always beneficial and can cause problems if improperly configured. If some devices (like a router) only support 1500 MTU, packets can be fragmented or dropped. Nevertheless, if you want to test out Jumbo Frames, run the following command to temporarily change the MTU of a network interface to 9000 bytes:
sudo ip link set venet0 mtu 9000