Configuring Loopback Test On A Layer 2 Ethernet Interface; Configuring Loopback On A Layer 3 Ethernet Interface - 3Com MSR 50 Series Configuration Manual

Configuring Loopback
Test on a Layer 2
Ethernet Interface
n
Configuring Loopback
on a Layer 3 Ethernet
Interface
You can enable loopback test to check whether the Ethernet interface functions
properly. Note that no data packets can be forwarded during the test. Loopback
test falls into the following two categories:
Internal loopback test, which is performed within switching chips to test the
■
functions related to the Ethernet interfaces.
External loopback test, which is used to test the hardware functions of an
■
Ethernet interface. To perform external loopback test on an Ethernet port, you
need to install a loopback plug on the Ethernet interface. In this case, packets
sent from the interface are received by the same interface.
Follow the following steps to configure Layer 2 Ethernet interface loopback test:
To do...
Enter system view
Enter Ethernet interface view
Enable loopback test
As for the internal loopback test and external loopback test, if a Layer 2
■
interface is down, only the former is available on it; if the interface is shut
down, both are unavailable.
The speed, duplex, mdi, and shutdown commands are not applicable during
■
a loopback test.
With the loopback test enabled, the Ethernet interface works in the full duplex
■
mode. With the loopback testing enabled, the original configurations will be
restored.
You can enable loopback on a Layer 3 Ethernet interface to check whether the
Ethernet interface functions properly. Note that interfaces with loopback enabled
cannot forward packets properly. Loopback on Layer 3 Ethernet interfaces falls
into the following two categories.
Internal loopback, used to check whether there is a fault on the chip's
■
functions related to the Ethernet interfaces.
External loopback, used to check whether there is a fault on the hardware
■
functions of an Ethernet interface.
Follow the following steps to configure Layer 3 Ethernet interface loopback:
To do...
Enter system view
Enter Ethernet interface view
Enable loopback on the
interface
General Ethernet Interface Configuration
Use the command...
system-view
interface interface-type
interface-number
loopback { external |
internal }
Use the command...
system-view
interface interface-type
interface-number
loopback { external |
internal }
91
Remarks
-
-
Optional
Disabled by default.
Remarks
-
-
Optional
Disabled by default.