HP 6120XG ProCurve Series 6120 Blade Switches Management and Configuration Gui - Page 292

Port Traffic Controls Jumbo Frames Troubleshooting A VLAN is configured to allow jumbo frames, but one or more ports drops all inbound jumbo frames. The port may not be operating at 1 gigabit or higher. Regardless of a port's configuration, if it is actually operating at a speed lower than 1 gigabit, it drops inbound jumbo frames. For example, if a port is configured for Auto mode (speed-duplex auto), but has negotiated a 100 Mbps speed with the device at the other end of the link, then the port cannot receive inbound jumbo frames. To determine the actual operating speed of one or more ports, view the Mode field in the output for the following command: show interfaces brief < port-list > A non-jumbo port is generating "Excessive undersize/giant frames" messages in the Event Log. The switches can transmit outbound jumbo traffic on any port, regardless of whether the port belongs to a jumbo VLAN. In this case, another port in the same VLAN on the switch may be jumboenabled through membership in a different, jumbo-enabled VLAN, and may be forwarding jumbo frames received on the jumbo VLAN to non-jumbo ports. Refer to "Outbound Jumbo Traffic" on page 12-10. 12-11