Port Traffic Controls

Jumbo Frames

Displaying the Maximum Frame Size

Use the show jumbos command to display the globally configured untagged maximum frame size for the switch.

ProCurve(config)# show jumbos

Jumbos Global Values

Configured :

MaxFrameSize

:

9216

Ip-MTU

:

9198

In Use

:

MaxFrameSize

:

9216

Ip-MTU

:

9198

Figure 14. Displaying the Maximum Frame Size and IP MTU ValuesOperating Notes for Maximum Frame Size

When you set a maximum frame size for Jumbo frames, it must be on a global level. You cannot use the jumbo max-frame-sizecommand on a per-port or per-VLAN basis.

The original way to configure Jumbo frames remains the same, which is per-VLAN, but you cannot set a maximum frame size per-VLAN.

Jumbo support must be enabled for a VLAN from the CLI or through SNMP.Setting the maximum frame size does not require a reboot.

When you upgrade to a version of software that supports setting the maximum frame size from a version that did not, the max-frame-sizevalue is set automatically to 9216 bytes.

Configuring a Jumbo maximum frame size on a VLAN allows frames up to max-frame-sizeeven though other VLANs of which the port is a member are not enabled for Jumbo support.

Operating Notes for Jumbo Traffic-Handling

ProCurve does not recommend configuring a voice VLAN to accept jumbo frames. Voice VLAN frames are typically small, and allowing a voice VLAN to accept jumbo frame traffic can degrade the voice transmission perfor­ mance.

You can configure the default, primary, and/or (if configured) the manage­ ment VLAN to accept jumbo frames on all ports belonging to the VLAN.

13-37