Web Management Guide-R04

Table Of Contents
Chapter 13
| Basic Administration Protocols
Connectivity Fault Management
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LTMs are sent as multicast CFM frames, and forwarded from MIP to MIP, with
each MIP generating a link trace reply, up to the point at which the LTM reaches
its destination or can no longer be forwarded.
LTMs are used to isolate faults. However, this task can be difficult in an Ethernet
environment, since each node is connected through multipoint links. Fault
isolation is even more challenging since the MAC address of the target node
can age out in several minutes. This can cause the traced path to vary over time,
or connectivity lost if faults cause the target MEP to be isolated from other
MEPs in an MA.
When using the command line or web interface, the source MEP used by to
send a link trace message is chosen by the CFM protocol. However, when using
SNMP, the source MEP can be specified by the user.
Parameters controlling the link trace cache, including operational state, entry
hold time, and maximum size can be configured on the Configure Global page
(see "Configuring Global Settings for CFM").
Parameters
These parameters are displayed:
MD Index – Domain index. (Range: 1-65535)
MA Index – MA identifier. (Range: 1-2147483647)
Source MEP ID – The identifier of a source MEP that will send the link trace
message. (Range: 1-8191)
Target
MEP ID – The identifier of a remote MEP that is the target of a link trace
message. (Range: 1-8191)
MAC Address – MAC address of a remote MEP that is the target of a link
trace message. This address can be entered in either of the following
formats: xx-xx-xx-xx-xx-xx or xxxxxxxxxxxx
TTL – The time to live of the link trace message. (Range: 0-255 hops)
Web Interface
To transmit link trace messages:
1. Click Administration, CFM.
2. Select Transmit Link Trace from the Step list.
3. Select an entry from MD Index and MA Index.
4. Specify the source MEP, the target MEP using either its MEP identifier or MAC
address, and set the maximum number of hops allowed in the TTL field.