Enabling Jumbo Frames for Improved Data Transfer

by Chris Sanders [Published on 28 June 2011 / Last Updated on 30 June 2010]

Jumbo frames are not anything new but they are often forgotten about. Enabling them may provide a bit of a performance boost. This tip shows how to do that.

Although it’s by no means anything new, a Jumbo frame is something that can have a very positive impact on your network given the right circumstances. The maximum size of a packet on an Ethernet network is typically 1,514 bytes, called the Maximum Transmission Unit (MTU). With Jumbo frames you can transmit packets as large as 9 KB. As you can imagine it takes significantly less effort to send one 9 KB packet as it does many 1,514 byte packets as long as your network supports it. Windows supports jumbo frames by default but since a fair number of network switches (especially small of the shelf switches) don’t support jumbo frames this feature is typically disabled on network cards of Windows hosts.

If your internal switching supports jumbo frames then you can enable it on the NIC of your Windows host quite easily. In order to do this type ncpa.cpl into the Run box to open up the Network Connections dialog. Right click the NIC whose setting you want changed and select Properties. Click on the Networking tab and select Configure. Select the Advanced tab and select Jumbo Frame. Change the value from its current value to a desired value (9,014 for instance), and click OK. You will lose connectivity for a brief moment but once this is finished your host should start taking advantage of its new larger MTU size.

See Also

The Author — Chris Sanders

Chris Sanders is a network security analyst for EWA Government Systems Inc. Chris is the author of the book Practical Packet Analysis as well as several technical articles. His personal website at www.chrissanders.org contains a great deal of information, articles, and guides related to network administration, network security, packet analysis, and general information technology.

Featured Links