Service Manual

Sending Loopback Messages and Responses
Loopback message and response (LBM, LBR), also called Layer 2 Ping, is an administrative echo transmitted by MEPs to verify
reachability to another MEP or MIP within the maintenance domain. LBM and LBR are unicast frames.
• Send a Loopback message
EXEC Privilege mode
ping ethernet domain name ma-name ma-name remote {mep-id | mac-addr mac-address}source {mep-id
| port interface}
Sending Linktrace Messages and Responses
Linktrace message and response (LTM, LTR), also called Layer 2 Traceroute, is an administratively sent multicast frames
transmitted by MEPs to track, hop-by-hop, the path to another MEP or MIP within the maintenance domain.
All MEPs and MIPs in the same domain respond to an LTM with a unicast LTR. Intermediate MIPs forward the LTM toward the
target MEP.
Figure 6. MPLS Core
Link trace messages carry a unicast target address (the MAC address of an MIP or MEP) inside a multicast frame. The destination
group address is based on the MD level of the transmitting MEP (01:80:C2:00:00:3[8 to F]). The MPs on the path to the target
MAC address reply to the LTM with an LTR, and relays the LTM towards the target MAC until the target MAC is reached or TTL
equals 0.
• Send a Linktrace message. There is no need to specify a destination, as the LTM is a Multicast message sent to the entire
ME.
EXEC Privilege
traceroute ethernet domain
802.1ag 92