21-14
Ethernet Card Software Feature and Configuration Guide, R7.2
January 2009
Chapter 21 Configuring RMON
Clearing the CRC-ALARM Wrap with the Clear CRC Error Command
Clearing the CRC-ALARM Wrap with the Clear CRC Error Command
The Cisco IOS CLI clear crc alarm interface interface-type interface-number command is intended to
clear the Cisco proprietary RPR wrap when it occurs due to FCS errors without corresponding
SONET/SDH errors. It is not intended to unwrap wraps due to other causes, such as SONET/SDH
defects or keep alive (KA) failures. If SONET/SDH or KA defects are present without FCS errors, the
software rejects the command with an error message. When FCS errors are present and SONET/SDH or
KA defects are present, the command is accepted by the software but the node unwraps only after all the
failures have been fixed. In this case, the user does not need to reissue the command after the
SONET/SDH or KA defect has cleared.
Note The unwrap does not occur immediately, but after conditions are met.
Step 3 ML_Series (config-if)# [no] trigger crc threshold
[threshold-value]
Sets an fcs error level as a percentage of bandwidth
to trip the SONET/SDH CRC-ALARM. Valid
values are:
2—10e-2 or 1% traffic (1 CRC error in100
packets)
3—10e-3 or 0.1% traffic (1 CRC error in 1000
packets) (default)
4—10e-4 or 0.01% traffic (1 CRC error in
10000 packets)
The no form of the command sets the level back to
the default threshold of 3.
Step 4 ML_Series (config-if)# [no] trigger crc action (Optional) Sets the CRC-ALARM to trigger a link
down for the reporting port. Set on an Cisco
proprietary RPR POS port, this also wraps the
Cisco proprietary RPR .
The no form of the command sets the trigger back to
the default off.
Step 5 ML_Series(config-if)# [no] trigger crc delay soak-time (Optional) Sets the minutes of soak time for
excessive CRC error detection. The valid value is
from 3 minutes to 10 minutes.
The no form of the command sets the delay back to
the default of one minute.
Step 6 ML_Series# end Return to privileged EXEC mode.
Step 7 ML_Series# show running-config Verify your entries.
Step 8 ML_Series# copy running-config startup-config (Optional) Save your entries in the configuration
file.
Command Purpose