from Huawei CLI – ping mac …, trace mac …

Huawei devices support generic MAC (GMAC) ping and trace on Layer 2 networks. Network administrators can use GMAC ping and trace functions to detect Layer 2 network faults, without configuring CFM.

ping mac mac-address vlan vlan-id [ interface interface-type interface-number | -c count | -s packetsize |-t timeout | -p priority-value ]

GMAC ping works at the same manner like 802.1ag MAC ping. It uses the Loopback Message and Loopback Reply (LBM/LBR) and is similar to ICMP ping function. GMAC ping can be used without configuring the MD (Maintenance Domain), MA (Maintenance Association), or MEP (Maintenance association End Point) on the source device, intermediate device, and destination device, as it is required when using 802.1ag. You only need to enable the GMAC function on the intermediate device. Therefore, GMAC ping is applicable to part of or a whole network without reference to MD, MA, and MEP configurations.

trace mac mac-address vlan vlan-id [ interface interface-type interface-number | -t timeout ] *

GMAC trace works at the same manner like 802.1ag MAC trace and uses Link Trace Message/Reply (LTR/LTM), so its function is similar to “trace route”. But GMAC trace can be implemented without configuring the MD, MA, or MEP on the source device, intermediate device, and the destination device. All the intermediate devices can respond with an LTR. Therefore, GMAC trace is applicable to part of or a whole network without reference to MD, MA, and MEP configurations.

Let’s see how these tools work.

First of all, both features have to be enabled on the source, intermediate and destination devices.

<labnarioSW1>sys
Enter system view, return user view with Ctrl+Z.
[labnarioSW1]ping mac enable
[labnarioSW1]trace mac enable

[labnarioSW1]ping mac 4c1f-cc86-2369 vlan 100
Pinging 4c1f-cc86-2369 with 95 bytes of data: 
Reply from 4c1f-cc86-2369: bytes = 117, time = 290ms
Reply from 4c1f-cc86-2369: bytes = 117, time = 30ms
Reply from 4c1f-cc86-2369: bytes = 117, time = 60ms
Reply from 4c1f-cc86-2369: bytes = 117, time = 50ms
Reply from 4c1f-cc86-2369: bytes = 117, time = 10ms
Packets: Sent = 5, Received = 5, Lost = 0 (0% loss)
Minimum = 10ms, Maximum = 290ms, Average = 88ms

[labnarioSW1]trace mac 4c1f-cced-ed92 vlan 100 interface Ethernet 0/0/1 
Tracing the route to 4c1f-cced-ed92 over a maximum of 255 hops:

Hops   Ingress MAC    Ingress Port    Ingress Action    Relay Action
       Egress MAC     Egress Port     Egress Action
 1     4c1f-cced-ed92 Ethernet0/0/1   IngOK             RlyHit
       --             --                          --
Info: Succeed in tracing the destination address 4c1f-cced-ed92.

GMAC ping and trace are part of Ethernet OAM.