Indicator Definitions
Chapter 7 Managing and Viewing Indicators 221
CRC Errors
Dest-Src Load
Reported for interfaces
Description reports packets that were damaged due to transmission errors as detected by the
Cyclic Redundancy Checksum (CRC) mathematical function, which ensures the
integrity of the data
■ on WAN interfaces, the proportion of packets with a CRC error received; a
high rate indicates poor physical line quality
■ on LAN interfaces, the number of CRC errors (they are expected to be rare);
presence indicates a poor quality connection or overly long or damaged cables
Units WAN interfaces: percentage of CRC errors
LAN interfaces: CRC errors per hour
Default
thresholds
■ WAN interfaces: minimum 10%–maximum 20%
■ LAN interfaces: minimum 0–maximum 1
Points to check For a WAN, check the state of the modems and connections for the router and for
the switch to which the router is connected.
For a LAN, check the state and length of the cables, and check that the cables are
properly connected to the device’s interface and to the link itself.
Reported for exchanges (RMON2, NetFlow)
Description traffic between two hosts: from destination host to source host
Units Kbps or Mbps
Default
thresholds
none
Points to check none
