Port Traffic Controls

Jumbo Frames

Jumbo IP MTU.

The IP MTU for Jumbos is supported with the following proprietary MIB object:

hpSwitchIpMTU OBJECT-TYPE

This is the value of the global Jumbos IP MTU (or L3 MTU) supported by the switch. The default value is set to 9198 bytes (a value that is 18 bytes less than the largest possible maximum frame size of 9216 bytes). This object can only be used in switches which support max-frame-sizeand ip-mtuconfiguration.

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 13. 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.

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