Ethernet Errors service

The Ethernet Errors service monitors the NIC interfaces on a device for the following issues: Alignment Errors, FCS Errors, Collisions, MAC Receive Errors, MAC Send Errors, Carrier Sense Errors, and frames that are too long.

The Ethernet Errors service only works with network infrastructure devices, such as switches, routers, fire walls, wireless access points. It will not work on servers, laptops, or workstations. To monitor NIC issues on those devices, use the Interface Health service.

Complete the steps below to monitor the Ethernet service on a device.

  1. Click View > All Devices and click the name of a device.
  2. Click Settings > Properties and ensure Use SNMP is selected.
  3. Click Save if required.
  4. Click Monitoring > Status.
  5. Click Add, enter 1 for the number of instances of the Ethernet Errors service.
  6. Click Apply.
  7. Click the Ethernet Errors service and then click the Service Details tab.
  8. In Interfaces to Monitor, select the NICs/ports that you would like to monitor.
  9. Click OK.

This service cannot use Self Healing.

Service TypeSNMP
Instances on a Device60
Device ClassServer - Generic, Workstation - Generic, Other, Printer, Scanner/Camera, Switch/Router, and Server - Windows
Monitored ByWindows probe
Interfaces to MonitorSelect the name or SNMP index of the NICs or ports that you would like to monitor.
Scan Interval60 minutes

To monitor the Ethernet Errors service on a device, you need to:

  • select the SNMP Enabled option when adding the device, and
  • add the Ethernet Errors service to the device and set the Interfaces to Monitor service detail.

The tables IF-MIB and EtherLike-MIB describe the SNMP objects that are queried by the probe.

EtherLike-MIB

Object DescriptorsNumerical OID
dot3StatsIndex1.3.6.1.2.1.10.7.2.1.1
dot3StatsAlignmentErrors1.3.6.1.2.1.10.7.2.1.2
dot3StatsFCSErrors1.3.6.1.2.1.10.7.2.1.3
dot3Stats1CollisionFrames1.3.6.1.2.1.10.7.2.1.4
dot3StatsMultipleCollisionFrames1.3.6.1.2.1.10.7.2.1.5
dot3StatsInternalMacReceiveErrors1.3.6.1.2.1.10.7.2.1.16
dot3StatsInternalMacTransmitErrors1.3.6.1.2.1.10.7.2.1.10
dot3StatsCarrierSenseErrors1.3.6.1.2.1.10.7.2.1.11
dot3StatsFrameTooLongs1.3.6.1.2.1.10.7.2.1.13

OID/Calculation

N-able N-central services use Reverse Polish Notation (RPN) for all calculation formulae.

Metric NameOID/CalculationDescription
Alignment Errors^ dot3StatsAlignmentErrorsAn Alignment Error can indicate the following about a received packet:
  • The number of bits in the received packet has an uneven byte count. That is, not an integral multiple of 8.
  • The received packet has a Frame Check Sequence (FCS) error.
  • Alignment Errors often result from MAC layer packet formation problems and cabling problems. These problems cause corruption of data, loss in data and the transmission of packets through more than two cascaded multi-port transceivers.
FCS Errors^ dot3StatsFCSErrorsFCS Errors, a type of cyclic redundancy checking, indicate that frames received by an interface are an integral number of octets long, but do not pass the FCS check.

Both Alignment Errors and FCS Errors can be caused by equipment powering up or down or by noise interference on unshielded twisted-pair (10BASE-T) segments. In a network that complies with the Ethernet standard, FCS Errors or Alignment Errors indicate bit errors during a transmission or reception. A very low rate is acceptable. Although Ethernet allows a 1 in 108 bit error rate, typical Ethernet performance is 1 in 1012 or better.
Collisions^ dot3Stats1CollisionFrames + ^ dot3StatsMultipleCollisionFramesCollisions indicate that two or more devices detect that the network is idle and try to send packets at exactly the same time within one round-trip delay. Because only one device can transmit at a time, both devices must stop sending and attempt to retransmit. Collisions are detected by the transmitting stations.

The retransmission algorithm helps to ensure that the packets do not retransmit at the same time. However, if the devices retry at nearly the same time, packets can collide again; the process repeats until either the packets finally pass onto the network without collisions, or 16 consecutive collisions occur and the packets are discarded.
MAC Receive Errors^ dot3StatsInternalMacReceiveErrorsMAC receive errors can indicate the malfunction of an Ethernet card on the subnet. You can identify the subnet and possibly the unit in question from the MAC address and the IP number.
MAC Send Errors^ dot3StatsInternalMacTransmitErrorsThis type of error indicates that the transmission failed because of an internal MAC sublayer error that is not caused by a collision or a carrier sense error.
Carrier Sense Errors^ dot3StatsCarrierSenseErrorsIndicates that the transmission failed because the carrier was not present during any or all of the transmission attempts.
Frame Too Long^ dot3StatsFrameTooLongsA packet that is longer than 1518 octets (including FCS octets) can cause a Frames Too Long Error. This type of error is often caused by a malfunction in the jabber protection mechanism on a transceiver, or the presence of excessive noise on the transmission cable.

The threshold value units are measured in packets.