Jumbo Frames

Jumbo frames are Ethernet frames that are larger than 1518 bytes. You can use Jumbo Frames to reduce server CPU utilization and increase throughput. However, additional latency may be introduced. 

NOTES: Jumbo Frames are supported at 1000 Mbps and 10Gbps. Using Jumbo Frames at 10 or 100 Mbps may result in poor performance or loss of link. End-to-end network hardware must support this capability; otherwise, packets will be dropped.

Jumbo Frames can be implemented simultaneously with VLANs and teaming.

To configure Jumbo Frames at the switch, consult your network administrator or switch user's guide.

Restrictions:

• Jumbo frames are not supported in multi-vendor team configurations.

• Supported protocols are limited to IP (TCP, UDP).

• Jumbo frames require compatible switch connections that forward Jumbo Frames. Contact your switch vendor for more information.

• When standard sized Ethernet frames (64 to 1518 bytes) are used, there is no benefit to configuring Jumbo Frames.

• The Jumbo Frames setting on the switch must be set to at least 8 bytes larger than the adapter setting for Microsoft* Windows* operating systems, and at least 22 bytes larger for all other operating systems.

• The 1000 Gigabit Server Adapter, 1000 PM Network Connection, 1000 PM Network Connection, 82562V 10/100 Network Connection, 82562GT 10/100 Network Connection, 82566DM Gigabit Network Connection, and the 82566DC Gigabit Network Connection do not support jumbo frames.

• The 1000 PL Network Connection supports jumbo frames in Microsoft* Windows* operating systems only when LAN software for Windows Device Manager is installed.

• The 1000 PT Quad Port Server Adapter, 1000 PT Desktop Adapter, 1000 PT Server Adapter, 1000 PF Server Adapter, 1000 PT Network Connection, 1000 PF Network Connection, 1000 PB Server Connection, 1000 PL Network Connection, 1000 EB Server Connection, 1000 PF Dual Port Server Adapter, 1000 PT Dual Port Server Adapter, 1000 PF Dual Port Server Connection, and 1000 PT Dual Port Network Connection do not support jumbo frames larger than 9238 bytes.

Setting Up Jumbo Frames in Microsoft* Windows*

NOTE: Jumbo frames are not supported in multi-vendor team configurations.

1. Open Microsoft* Windows* Device Manager.

2. Open Properties on your adapter.

3. Click the Advanced tab.

4. Select Jumbo Frames from the list of advanced features.

5. Set your desired packet size (based on network capability).

6. Click OK to apply the changes. 

All equipment on the network must also support the larger frame size. When setting up Jumbo Frames on other network devices, be aware that different network devices calculate Jumbo Frame size differently. Some devices include the header information in the frame size while others do not. network adapters do not include header information in the frame size. When configuring Jumbo Frames on a switch, set the frame size four bytes higher for CRC, plus four bytes if you are using VLANs or QoS packet tagging.

Last modified on 9/12/06 8:40a Revision 13