Mac Swap Loopback Overview; Mac Swap Loopback Features Supported By The S3700 - Huawei Quidway S3700 Series Configuration Manual

Quidway S3700 Series Ethernet Switches
Configuration Guide - Reliability

9.1 MAC Swap Loopback Overview

The MAC swap loopback function modifies the header of a received Ethernet frame by swapping
the source and destination MAC addresses so that the Ethernet frame can be sent back to the
sender. This function checks Ethernet connectivity and network performance.
The MAC swap loopback technique can work with a network performance tester to test the
connectivity, throughput, and QoS of an Ethernet network.
A MAC swap loopback test can be performed only for Ethernet frames with IP payload.

9.2 MAC Swap Loopback Features Supported by the S3700

The S3700 supports local MAC swap loopback test and remote MAC swap loopback test.
Local MAC Swap Loopback Test
A local MAC swap loopback test checks connectivity and performance of the network between
a tester and a tested switch, and performance of the tested switch. As shown in
Ethernet frames sent by a tester traverse an Ethernet network and reach the tested switch
(SwitchB). After the tested switch receives the Ethernet frames, it forwards them to the interface
where local MAC swap loopback is configured. The tested switch swaps source and destination
MAC addresses of all Ethernet frames that match the local MAC swap loopback configuration
and sends the Ethernet frames back to the tester through the specified outbound interface. The
tester then analyzes network performance based on Ethernet frames sent from the tested switch.
When a local MAC swap test is performed on an interface, services on the interface are
interrupted, but services on other interfaces are not affected. If a large number of test packets
are sent, test packets occupy bandwidth of other services on the interface that sends test packets
back to the tester.
Figure 9-1 Local MAC swap loopback test
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Remote MAC Swap Loopback Test
A remote MAC swap loopback test checks connectivity and performance of the network between
a tester and a tested switch but does not check performance of the tested switch. As shown in
Figure
switch (SwitchB). After the uplink interface of the tested switch receives the Ethernet frames,
Issue 01 (2011-10-26)
SwitchA
9-2, Ethernet frames sent by a tester traverse an Ethernet network and reach the tested
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Tester
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Ethernet
9 MAC Swap Loopback Configuration
Figure
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SwitchB Users
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