Configuration Restrictions And Guidelines; Configuration Procedure; Configuring Jumbo Frame Support - HP 5120 EI Series Lan Switching Configuration Manual

External loopback testing—Tests hardware of Ethernet interfaces. To perform external loopback
•
testing on an Ethernet interface, connect a loopback plug to the Ethernet interface. The switch sends
test packets out of the interface, which are expected to loop over the plug and back to the interface.
If the interface fails to receive any test packet, the hardware of the interface is faulty.
An Ethernet interface in a loopback test does not forward data traffic.

Configuration restrictions and guidelines

On an interface administratively shut down, you can perform neither internal nor external loopback
•
testing.
• During loopback testing, the Ethernet interface operates in full duplex mode. When you disable
loopback testing, the interface returns to its duplex setting.
Loopback testing is a one-time operation, and is not recorded in the configuration file.
•

Configuration procedure

To enable loopback testing on an Ethernet interface:
Step
1. Enter system view.
2. Enter Ethernet interface view.
3. Enable loopback testing.

Configuring jumbo frame support

An Ethernet interface might receive some frames larger than the standard Ethernet frame size (called
"jumbo frames") during high-throughput data exchanges such as file transfers. Usually, an Ethernet
interface discards jumbo frames. With jumbo frame support enabled, the interface can process frames
larger than the standard Ethernet frame size yet within the specified range.
In interface configuration mode (Ethernet interface view or port group view), you can set the length of
jumbo frames that are allowed to pass through the Ethernet interface.
If you execute the command in Ethernet interface view, the configuration takes effect only on the
•
interface.
If you execute the command in port group view, the configuration takes effect on all ports in the port
•
group.
To configure jumbo frame support in interface view or port group view:
Step
1. Enter system view.
Enter Ethernet
2.
interface view.
Command
system-view
interface interface-type
interface-number
loopback { external | internal }
Command
system-view
interface interface-type
interface-number
7
Remarks
N/A
N/A
Optional.
Disabled by default.
Remarks
N/A
N/A