R2511-HP MSR Router Series Interface Configuration Guide(V5)

5
Configuring
physical state
change
suppression on
an Ethernet
interface
No
Available
only on
Layer 3 GE
interfaces
No No
Available
only on
Layer 3 GE
interfaces
Available
only on
Layer 3 GE
interfaces
No
The physical link state of an Ethernet interface is either up or down. Each time the physical link of a port
goes up or comes down, the system immediately reports the change to the upper-layer protocol modules
(such as routing and forwarding modules) for packet transmission, and automatically generates traps
and logs, informing the user to take corresponding actions.
By default, an Ethernet interface detects the physical state change every 5 seconds. When a physical
state change occurs, the Ethernet interface can detect the change within 0 to 5 seconds. To enable the
system to report the physical state change as soon as the change occurs, you can set the suppression
interval to 0 seconds (disable physical state change suppression).
To configure physical state change suppression on an Ethernet interface:
Step Command Remarks
1. Enter system view.
system-view N/A
2. Enter Ethernet interface view.
interface interface-type
interface-number
N/A
3. Set a physical state change
suppression interval.
link-delay delay-time
Optional.
By default, an Ethernet interface
detects the physical state change
every 5 seconds.
Configuring loopback testing on an Ethernet interface
If an Ethernet interface does not work correctly, you can enable loopback testing on it to identify the
problem. An Ethernet interface in a loopback test does not forward data traffic.
Loopback testing has the following types:
• Internal loopback testing—Tests all on-chip functions related to Ethernet interfaces.
• 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 device 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 packets, the hardware of the interface is faulty.
Configuration restrictions and guidelines
• On an interface that is physically down, you can only perform internal loopback testing. On an
interface administratively shut down, you cannot perform internal or external loopback testing.
• The speed, duplex, mdi, and shutdown commands are not available during loopback testing.
• During loopback testing, the Ethernet interface operates in full duplex mode. When you disable
loopback testing, the port returns to its duplex setting.
Configuration procedure
To enable loopback testing on an Ethernet interface: