To do…
Use the command…
Remarks
Enter system view
system-view
—
Configure jumbo frame support
jumboframe enable
Optional
By default, an Ethernet interface accepts
jumbo frames (up to 2048 bytes).
Enabling loopback detection on an Ethernet interface
Enabling single-port loopback detection on an Ethernet Interface
If an interface receives a packet that it sent, a loop occurs. Loops might cause broadcast storms,
degrading network performance. You can use loopback detection to detect loops on an interface and
configure the protective action to take on the interface when a loop is detected, for example, to shut
down the interface. Depending on whether a protective action is configured, the device takes the actions
to alleviate the impact of the loop condition.
Table 1
Actions to take upon detection of a loop condition
Actions
Port type
No protective action is configured
A protective action is configured
Access port
•
Place the receiving interface in controlled
mode. The interface does not receive or send
packets.
•
Generate traps.
•
Delete all MAC address entries of the
interface.
•
Perform the configured protective
action.
•
Generate traps and log messages.
•
Delete all MAC address entries of the
interface.
Hybrid or trunk
port
•
Generate traps.
•
If loopback detection control is enabled,
place the receiving interface in controlled
mode. The interface does not receive or send
packets.
•
Delete all MAC address entries of the
interface.
•
Create traps and log messages.
•
If loopback detection control is
enabled, take the configured
protective action on the interface.
•
Delete all MAC address entries of the
interface.
Follow these steps to configure single-port loopback detection:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enable global loopback detection
loopback-detection enable
Required
Disabled by default.
Set the loopback detection interval
loopback-detection interval-time
time
Optional
30 seconds by default.
Enter Ethernet
interface view
Enter Ethernet
interface view
interface
interface-type
interface-number
Use either command.
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