Manualshelf

Troubleshooting Guide

ManualsBrandsExtreme Networks ManualsComputers & AccessoriesFabric-enabled multi-service edge switches
141142143144145146147148149150
Table Of Contents
Fault detection and notification are achieved through the use of Continuity Check Messages (CCM).
CCM messages are not supported in the current release.
Fault verification
Fault verification is achieved through the use of Loopback Messages (LBM). An LBM is a unicast
message triggered by the operator issuing an operational command. LBM can be addressed to
either a MEP or Maintenance Intermediate Point (MIP) but only a MEP can initiate an LBM. The
destination MP can be addressed by its MAC address. The receiving MP responds with a Loopback
Response (LBR). LBM can contain an arbitrary amount of data that can be used to diagnose faults
as well as performance measurements. The receiving MP copies the data to the LBR.
LBM message
The LBM packet is often compared to a ping. A MEP transmits the LBM packet. This packet can be
addressed to another MEP or to the MAC address of the MP; in the case of SPBM, this is the SPBM
system ID or its virtual SMLT MAC. Only the MP for which the packet is addressed responds with an
LBR message.
• Provides “ICMP ping like” functionality natively at Layer-2.
• DA is the MAC address of the target.
• Includes a transaction identifier that allows the corresponding LBR to be identified when more
than one LBM request is waiting for a response.
• Bridges forward the frame using the normal FDB rules.
• Only the target (MIP or MEP) responds.
• Initiator can choose the size and contents data portion of the LBM frame.
• Can be used to check the ability of the network to forward different sized frames.
l2ping
The l2 ping command is a proprietary command that allows a user to trigger an LBM message.
For B-VLANs, specify either the destination MAC address or node name.
This provides a simpler command syntax than the standard LBM commands, which require the user
to specify the MD, MA, and MEP ID information. The l2 ping command provides a ping equivalent
at Layer 2 for use with nodes on the SPBM B-VLAN in the customer domain. SPBM B-VLANs
support the SMLT virtual option for the source mode.
Operations and Management
January 2017 Troubleshooting 148
Comments on this document? infodev@avaya.com