LevelOne GTL-2691 - Manual (Page 495)

C HAPTER 14 | 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" ).
P ARAMETERS
These parameters are displayed:
◆ MD Index – Domain index. (Range: 1-65535)
◆ MA Index – MA identifier. (Range: 0-4094)
◆ 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)
W EB I NTERFACE
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.