Enabling GMAC Trace to Locate Faults

Context

Similar to IP traceroute, GMAC trace efficiently detects and locates Ethernet faults and monitors the link quality.

GMAC trace is applicable to the network where MD, MA, or MEP is not configured.

Procedure

Configure the devices on both ends of a link and the intermediate device.
Perform the following operations on the devices at both ends of the link to be tested and the intermediate device.
1. Run the system-view command to enter the system view.
2. Run the trace mac enable command to enable GMAC trace globally.
  By default, GMAC trace is disabled (except the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S).
  
  After GMAC trace is enabled on the device, GMAC trace operations can be performed on the device. The device can respond to received GMAC trace packets.
Perform GMAC trace.
Perform the following operations on the device at one end of the link to be tested.
1. Run the system-view command to enter the system view.
2. Run the trace mac mac-address vlan vlan-id [ interface interface-type interface-number | -t timeout | -h ]^* command to configure the device to locate connectivity faults between the local and remote devices.
  A MEP is not required to initiate GMAC trace, but the destination node cannot be a MEP or MIP. GMAC trace can be used without configuring the MD, MA, or MEP on the source device, intermediate device, or destination device. All the intermediate devices can respond with an LTR.
  
  The two devices must be configured with IEEE 802.1ag of the same version. Otherwise, you cannot use the trace mac command. For example, if the local device is configured with IEEE 802.1ag Draft 7 and the remote device is configured with IEEE Standard 802.1ag-2007, the connectivity fault cannot be located.