Link Trace Messages (LTM) are multicast frames transmitted by a MEP to track the path (hopby-hop) to a destination MEP. Each receiving MEP sends a trace route reply directly to the originating MEP, and regenerates the trace route message. LTM are discussed in IEEE 802.1ag.
â–¶ To start the link trace messages
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Access the page SOAM â–¶ CFM â–¶ MEP â–¶ LTM.
All existing link trace information for Maintenance association End Points is displayed. -
Click the MEPID of the MEP for which you want to start the LTM.
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Complete the required fields, then click Start.
For more information on specific parameters, refer to the following tables.
MEP Link Trace (SOAM â–¶ CFM â–¶ MEP â–¶ LTM)
| Parameter | Description |
|---|---|
| MEP Index Index |
Index of the Maintenance association End Point |
| MEPID | Maintenance association End Point Identifier |
| Target Type | Link trace target by remote MEPID or MAC address. |
| Remote MEPID R-MEPID |
Targeted remote MEPID. The remote MEP MAC address is resolved into the local MEP database. |
| LTR Received | The number of link trace responses received by this MEP |
| MAC Address | Target MAC address. Only unicast MAC addresses are valid for link trace target address. |
| TTL | Link trace time to live. Range: 0–255 If it is initially set to 0, no response should be received. |
| Set FDB Only Flag | Enables the LTM to set the flag "UseFDBonly" (IEEE 802.1ag) or the flag "HWonly" (Y.1731) |
Bottom of Table
| Parameter | Description |
|---|---|
| LTM Sequence Number Next Seq. # |
Sequence number used by the latest link trace request initiated from that ME |
| Target MAC Address Target MAC |
Target MAC address used by the latest link trace request |
| TTL | Link trace time to live received in link trace responses. |
| F | Forwarded. Indicates that the responder maintenance point did forward the LTM. |
| T | Terminal MEP. Indicates that the responder maintenance point is a MEP. |
| Action | Indicates how the responder system processes frames targeted for the destination address specified by the LTM Possible values are:
|
| TLV Type | Indicates which Type Length Values (TLVs) are included in link trace responses |
| TLV Value | The TLV values included in link trace responses |
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