C
HAPTER
14
| Basic Administration Protocols
Connectivity Fault Management
– 535 –
TRANSMITTING LINK
TRACE MESSAGES
Use the Administration > CFM (Transmit Link Trace) page to transmit link
trace messages (LTMs). These messages can isolate connectivity faults by
tracing the path through a network to the designated target node (i.e., a
remote maintenance end point).
CLI REFERENCES
â—† "CFM Commands" on page 1319
COMMAND USAGE
â—† LTMs can be targeted to MEPs, not MIPs. Before sending a link trace
message, be sure you have configured the target MEP for the specified
MA (see "Configuring Remote Maintenance End Points").
â—† If MAC address of target MEP has not been learned by any local MEP,
then the linktrace may fail. Use the Show Remote MEP page (see
"Displaying Remote MEPs") to verify that a MAC address has been
learned for the target MEP.
â—† 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.
â—† 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.
â—† 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.
â—† 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)
â—† Target
â–
MEP ID – The identifier of a remote MEP that is the target of a link
trace message. (Range: 1-8191)
To Next Page
Loading...
Need help?
General
