H3C Technologies H3C S10500 Series Switches - Manual (Page 34)

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Table 9 Relationship between the interval field value, the interval between CCM messages, and the
timeout time of the remote MEP
The interval field value
The interval between CCM
messages
The timeout time of the remote
MEP
3 100 milliseconds 350 milliseconds
4 1 second 3.5 seconds
5 10 second 35 seconds
6 60 seconds 210 seconds
7 600 seconds 2100 seconds
Configuring LB on MEPs
The LB function can verify the link state between the local MEP and the remote MEP or MIP.
Follow these steps to configure LB on a MEP:
To do... Use the command... Remarks
Enable LB
cfd loopback service-instance
instance-id mep mep-id { target-mep
target-mep-id | target-mac
mac-address } [ number number ]
Required
Disabled by default.
Available in any view
Configuring LT on MEPs
LT can trace the path between the source and target MEPs and can also locate link faults by sending LT
messages automatically. The two functions are implemented in the following way:
• To implement the first function, the source MEP first sends LTM messages to the target MEP. Based
on the LTR messages in response to the LTM messages, the path between the two MEPs can be
identified.
• In the latter case, after LT messages automatic sending is enabled, if the source MEP fails to receive
the CCM frames from the target MEP within 3.5 times the transmission interval, the link between the
two is considered faulty, and LTM frames (with the target MEP as the destination and the TTL field
in the LTM frames set to the maximum value 255) will be sent out. Based on the LTRs that the MIPs
return, the fault source can be located.
Follow these steps to configure LT on MEPs:
To do... Use the command... Remarks
Find the path between a source
MEP and a target MEP
cfd linktrace service-instance instance-id
mep mep-id { target-mep target-mep-id |
target-mac mac-address } [ ttl ttl-value ]
[ hw-only ]
Required
Available in any view
Enter system view system-view —
Enable LT messages automatic
sending cfd linktrace auto-detection [ size
size-value ] Required
Disabled by default.