R3102-R3103-HP 6600/HSR6600 Routers High Availability Configuration Guide
23
LB
Similar to ping at the IP layer, loopback verifies the connectivity between a source device and a
target device. To implement this function, the source MEP sends loopback messages (LBMs) to the
target MEP. Depending on whether the source MEP can receive a loopback reply message (LBR) from
the target MEP, the link state between the two can be verified. LBM frames and LBR frames are unicast
frames.
LT
Linktrace is similar to traceroute. It identifies the path between the source MEP and the target MEP.
This function is implemented in the following way—the source MEP sends the linktrace messages
(LTMs) to the target MEP. After receiving the messages, the target MEP and the MIPs that the LTM
frames pass send back linktrace reply messages (LTRs) to the source MEP. Based on the reply
messages, the source MEP can identify the path to the target MEP. LTM frames are multicast frames
and LTRs are unicast frames.
Protocols and standards
IEEE 802.1ag, Virtual Bridged Local Area Networks Amendment 5: Connectivity Fault Management
CFD configuration task list
For CFD to work correctly, design the network by performing the following tasks:
Grade the MDs in the entire network, and define the boundary of each MD.
Assign a name to each MD. Make sure that the same MD has the same name on different
devices.
Define the MA in each MD according to the VLAN you want to monitor.
Assign a name to each MA. Make sure that the same MA in the same MD has the same name
on different devices.
Determine the MEP list of each MA in each MD. Make sure that devices in the same MA
maintain the same MEP list.
At the edges of MD and MA, MEPs should be designed at the device port. MIPs can be
designed on devices or ports that are not at the edges.
Complete the following tasks to configure CFD:
Tasks
Remarks
Configuring basic CFD
settings
Enabling CFD
Required.
Configuring the CFD protocol version
Optional.
Configuring MEPs
Required.
Configuring MIP generation rules
Required.
Configuring CFD
functions
Configuring CC on MEPs
Required.
Configuring LB on MEPs
Optional.
Configuring LT on MEPs
Optional.