Zte ZXR10 2920 User Manual

ZXR10 2920/2928/2952
(V1.0) Access Switch User Manual （Volume I）
294 Confidential and Proprietary Information of ZTE CORPORATION
Single Loop Test Method
Single-port loop test is to check whether a loop exists in the
ports of the switch. If such a loop exists, it may result in
errors in learning MAC addresses and may easily cause a
broadcast storm. In worse cases, switch and network may be
down. Starting the single-port loop test and disabling the port
with loop can efficiently avoid the influence caused by port loop.
Working principle of single-port loop test, switch sends a test
message on a port, if the test message comes back on the port
without any changes or just is added a tag, it indicates that a
loop exists on this port.
The switch sends a test packet through a port. If this test
packet is received through the port without any change (or only
a tag is attached), it indicates that a loop exists in this port.
The test packet sent by the switch includes the following three
parameters:
It indicates the MAC address of the switch. The MAC address of
each switch is unique.
Port numbers correspond to the numbers of the ports on the
switch one by one.
For each switch, the digital signature of each port is different.
When three parameters in the test packet sent through port are
same as those in the test packet received through the port, a
port loop absolutely exists.
Configuring Single-Port Loop Test
This topic describes the configuration of single-port loop test.
For the configuration of single-port loop test, perform the
following steps.
1. To enable/disable loop test function of specified port, use
command set loopdetect port <portlist> {enable|disable}
in global config mode. This is shown in
Table 437.
TABLE 437 SET LOOP DETECT PORT COMMAND
Format Mode Function
set loopdetect
port <portlist>
{enable|disable
global config This enable/disable
loop test function of
specified port
Result: This enable/disable loop test function of specified
port.
Note: By default, port loop test function is disabled.
Features of
Singly Port
Loop
Principle of
Single Port
Loop Test
Source MAC
address
Port Number
Discimination
Field
Purpose
Steps

Zte ZXR10 2920 Specifications

General

Brand	Zte
Model	ZXR10 2920
Category	Switch
Language	English