12-8
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-size and ip-mtu configuration.
Displaying the Maximum Frame Size
Use the show jumbos command to display the globally configured untagged
maximum frame size for the switch.
Figure 13. Displaying the Maximum Frame Size and IP MTU Values
Operating 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-size command 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-size
value is set automatically to 9216 bytes.
■ Configuring a Jumbo maximum frame size on a VLAN allows frames
up to max-frame-size even though other VLANs of which the port is a
member are not enabled for Jumbo support.
ProCurve(config)# show jumbos
Jumbos Global Values
Configured : MaxFrameSize : 9216 Ip-MTU : 9198
In Use : MaxFrameSize : 9216 Ip-MTU : 9198
