Understanding ml-series card crc error threshold – Cisco 15327 User Manual

Page 350

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21-6

Ethernet Card Software Feature and Configuration Guide, R7.2

Chapter 21 Configuring RMON

Collecting Group Ethernet Statistics on an Interface

Collecting Group Ethernet Statistics on an Interface

Beginning in privileged EXEC mode, follow these steps to collect group Ethernet statistics on an
interface. This procedure is optional.

To disable the collection of group Ethernet statistics, use the no rmon collection stats index interface
configuration command.

This example shows how to collect RMON statistics for the owner root:

ML_Series(config)# interface gigabitethernet1

ML_Series(config-if)# rmon collection stats 2 owner root

Understanding ML-Series Card CRC Error Threshold

The POS ports on the ML-Series card report alarms for SONET/SDH defects and GFP defects, including
signal fail (SF) and signal degrade (SD) alarms. In most circumstances, these alarms alert the user to
problems that also cause excessive CRC errors on the POS port. But there are situations where excessive
CRC errors will occur on the POS port, but the link will not have any SONET defects or GFP defects to
report. Examples of this situation include an ML-Series card at the other end of the link sending out
packets with CRC errors or a bit error rate too low to trigger SF or SD defect, but high enough to cause
a meaningful CRC packet error rate.

In these situations with a default ML-Series card Cisco proprietary RPR implementation and no reported
SONET/SDH or GFP defects, the POS interface remains in the up state as a member of the shared packet
ring (SPR) interface. Traffic is lost quietly and does not trigger any alarms or action.

The FCS threshold configuration and detection feature fixes this problem. The user can now configure
the ML-Series card to raise an alarm if the percentage of packet loss due to CRC errors crosses a
configureable threshold. The alarm raised is the CRC Threshold Crossing Alarm (CRC-ALARM), which
is a service-affecting (SA) SONET/SDH alarm with a Major (MA) severity. Reported SONET/SDH
alarms can be viewed under the Alarms tab of CTC.

Command

Purpose

Step 1

configure terminal

Enter global configuration mode.

Step 2

interface interface-id

Specify the interface on which to collect statistics, and enter
interface configuration mode.

Step 3

rmon collection stats index [owner ownername] Enable RMON statistic collection on the interface.

For index, specify the RMON group of statistics. The range
is from 1 to 65535.

(Optional) For owner ownername, enter the name of the
owner of the RMON group of statistics.

Step 4

end

Return to privileged EXEC mode.

Step 5

show running-config

Verify your entries.

Step 6

show rmon statistics

Display the contents of the ML-Series card statistics table.

Step 7

copy running-config startup-config

(Optional) Save your entries in the configuration file.

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