Nexus Interfaces Test

This test monitors each network interface of the Cisco Nexus Switch and reports the availability and operation state of each network interface. This test also helps administrators in figuring out how well data was transmitted to and from the network interface and the errors encountered in each network interface while data was transmitted/received. Using this test, administrators can identify the network interface that is handling too much of data traffic and the network interface that is error-prone.

Target of the test : A Cisco Nexus Switch

Agent deploying the test : An external agent

Outputs of the test : One set of results for each network interface of the target Cisco Nexus Switch being monitored.

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed

Host

The IP address of the Cisco Nexus Switch to be monitored.

SNMPPort

The port at which the monitored target exposes its SNMP MIB; the default is 161.

SNMPVersion

By default, the eG agent supports SNMP version 1. Accordingly, the default selection in the SNMPversion list is v1. However, if a different SNMP framework is in use in your environment, say SNMP v2 or v3, then select the corresponding option from this list.

SNMPCommunity

The SNMP community name that the test uses to communicate with the firewall. This parameter is specific to SNMP v1 and v2 only. Therefore, if the SNMPVersion chosen is v3, then this parameter will not appear.

Username

This parameter appears only when v3 is selected as the SNMPversion. SNMP version 3 (SNMPv3) is an extensible SNMP Framework which supplements the SNMPv2 Framework, by additionally supporting message security, access control, and remote SNMP configuration capabilities. To extract performance statistics from the MIB using the highly secure SNMP v3 protocol, the eG agent has to be configured with the required access privileges – in other words, the eG agent should connect to the MIB using the credentials of a user with access permissions to be MIB. Therefore, specify the name of such a user against this parameter. 

Context

This parameter appears only when v3 is selected as the SNMPVersion. An SNMP context is a collection of management information accessible by an SNMP entity. An item of management information may exist in more than one context and an SNMP entity potentially has access to many contexts. A context is identified by the SNMPEngineID value of the entity hosting the management information (also called a contextEngineID) and a context name that identifies the specific context (also called a contextName). If the Username provided is associated with a context name, then the eG agent will be able to poll the MIB and collect metrics only if it is configured with the context name as well. In such cases therefore, specify the context name of the Username in the Context text box.  By default, this parameter is set to none.

AuthPass

Specify the password that corresponds to the above-mentioned Username. This parameter once again appears only if the SNMPversion selected is v3.

Confirm Password

Confirm the AuthPass by retyping it here.

AuthType

This parameter too appears only if v3 is selected as the SNMPversion. From the AuthType list box, choose the authentication algorithm using which SNMP v3 converts the specified username and password into a 32-bit format to ensure security of SNMP transactions. You can choose between the following options:

  • MD5 - Message Digest Algorithm
  • SHA - Secure Hash Algorithm
  • SHA224 - Secure Hash Algorithm 224 bit
  • SHA256 - Secure Hash Algorithm 256 bit
  • SHA384 - Secure Hash Algorithm 384 bit
  • SHA512 - Secure Hash Algorithm 512 bit

EncryptFlag

This flag appears only when v3 is selected as the SNMPversion. By default, the eG agent does not encrypt SNMP requests. Accordingly, the this flag is set to No by default. To ensure that SNMP requests sent by the eG agent are encrypted, select the Yes option. 

EncryptType

If the EncryptFlag is set to Yes, then you will have to mention the encryption type by selecting an option from the EncryptType list. SNMP v3 supports the following encryption types:

  • DES - Data Encryption Standard
  • 3DES - Triple Data Encryption Standard
  • AES - Advanced Encryption Standard
  • AES128 - Advanced Encryption Standard 128 bit
  • AES192 - Advanced Encryption Standard 192 bit
  • AES256 - Advanced Encryption Standard 256 bit

EncryptPassword

Specify the encryption password here.

Confirm Password

Confirm the encryption password by retyping it here.

Timeout

Specify the duration (in seconds) within which the SNMP query executed by this test should time out in this text box. The default is 10 seconds.

Data Over TCP

By default, in an IT environment, all data transmission occurs over UDP. Some environments however, may be specifically configured to offload a fraction of the data traffic – for instance, certain types of data traffic or traffic pertaining to specific components – to other protocols like TCP, so as to prevent UDP overloads. In such environments, you can instruct the eG agent to conduct the SNMP data traffic related to the monitored target over TCP (and not UDP). For this, set this flag to Yes. By default, this flag is set to No.

EngineID

This parameter appears only when v3 is selected as the SNMPVersion. Sometimes, the test may not report metrics when AES192 or AES256 is chosen as the Encryption type. To ensure that the test report metrics consistently, administrators need to set this flag to Yes. By default, this parameter is set to No.

Measurements made by the test
Measurement Description Measurement Unit Interpretation

Is the network interface operationally available?

Indicates the availability of this network interface.

 

If the operational state (i.e., the running state) of an interface is "up", then, this measure will report the value Yes. If the operational status of an interface is “down”, then this measure will report the value No. On the other hand, if the admin state (i.e., the configured state) of an interface is “down”, then the value of this measure will be: Administratively Down.

The numeric values that correspond to each of the above-mentioned states are as follows:

Measure value Numeric Value
No 0
Yes 100
Administratively Down 200
Dormant 300
Not Present 400

Note:

By default, this measure reports one of the Measure Values listed in the table above to indicate the status of an interface. The graph of this measure however, represents the same using the numeric equivalents – 0 to 300.

Data transmitted rate

Indicates the rate of data being transmitted from the router over a network link.

MB/Sec

This measurement depicts the workload on a network link.

Data received rate

The rate of data being received by the router over a network link.

MB/Sec

This measure also characterizes the workload on a network link.

Speed

Indicates the speed of this network interface.

Mbps

Some network interface may dynamically change their speed over time - based on external factors/settings. By tracking the speed of an interface over time, an administrator can be aware of such speed changes.

Bandwidth used

Indicates the percentage utilization of the bandwidth available over a network link.

Percent

A value close to 100% indicates a network bottleneck.

Note:

The speed of a network interface is based on the value of its SNMP MIB-II variable, which is set using router-specific commands (e.g., the "bandwidth" command of a Cisco router). When a network interface has a fixed maximum speed limit (e.g., Ethernet), the percentage bandwidth will be <= 100%.

In some instances, service providers offer a minimum committed information rate (CIR). In such cases, the speed of the network interface is not fixed and may be set to the minimum CIR. Since user traffic may be in excess of the CIR at times, the percentage bandwidth measure could exceed 100%. In such cases, the percentage bandwidth measure is to be ignored.

Receive errors

Indicates the rate of inbound packets that contained errors preventing them from being delivered to a higher-layer protocol.

Packets/Sec

Ideally, this value should be 0.

Transmit errors

Indicates the rate at which outbound packets could not be delivered as they contained errors.

Packets/Sec

Ideally, this value should be 0.

In discards

Indicates the rate at which inbound packets were discarded, though such packets did not contain any errors that could prevent them from being delivered to a higher-layer protocol.

Packets/Sec

One possible reason for discarding such a packet could be to free up buffer space.

Out discards

Indicates the rate at which outbound packets were discarded, though such packets did not contain any errors that could prevent them from being delivered to a higher-layer protocol.

Packets/Sec

One possible reason for discarding such a packet could be to free up buffer space.

If you have a large number of out discards, it means that the network device's output buffers have filled up and the device had to drop these packets. This can be a sign that this segment is run at an inferior speed and/or duplex, or there is too much traffic that goes through this port.

Non-unicast packets received

Indicates the rate at which packets which were addressed as multicast or broadcast were received by this layer.

Packets/Sec

 

Non-unicast packets transmitted

Indicates the rate at which packets which were addressed as multicast or broadcast were sent by this layer.

Packets/Sec

 

Unicast packets received

Indicates the rate at which packets which were not addressed as multicast or broadcast were received by this layer.

Packets/Sec

 

Unicast packets transmitted

Indicates the rate at which packets which were not addressed as multicast or broadcast were sent by this layer.

Packets/Sec

 

Queue length

Indicates the length of the output packet queue.

Number

A consistent increase in the queue length could be indicative of a network bottleneck.

Unknown protocols

Indicates the rate at which unknown protocols were received.

Packets/Sec

For packet-oriented interfaces, this measure will report the number of packets received via the interface which were discarded because of an unknown or unsupported protocol. For character-oriented or fixed-length interfaces that support protocol multiplexing, this measure reports the number of transmission units received via the interface which were discarded because of an unknown or unsupported protocol. For any interface that does not support protocol multiplexing, this counter will always be 0.

Operation state down reason

Indicates the current operation state of this network interface.

 

The values reported by this measure and its numeric equivalents are mentioned in the table below:

State Numeric Value
Error Disabled 0
Other 1
None 2
Hwfailure 3
LoopbackDiagFailure 4
SwFailure 6
LinkFailure 7
Offline 8
NonParticipating 9
Initializing 10
VsanInactive 11
AdminDown 12
ChannelAdminDown 13
ChannelOperSuspended 14
ChannelConfigurationInProgress 15
RcfInProgress 16
ElpFailureIsolation 17
EscFailureIsolation 18
DomainOverlapIsolation 19
DomainAddrAssignFailureIsolation 20
DomainOtherSideEportIsolation 21
DomainInvalidRcfReceived 22
DomainManagerDisabled 23
ZoneMergeFailureIsolation 24
VsanMismatchIsolation 25
ParentDown 26
SrcPortNotBound 27
InterfaceRemoved 28
FcotNotPresent 29
FcotVendorNotSupported 30
IncompatibleAdminMode 31
IncompatibleAdminSpeed 32
SuspendedByMode 33
SuspendedBySpeed 34
SuspendedByWWN 35
DomainMaxReTxFailure 36
EppFailure 37
portVsanMismatchIsolation 38
LoopbackIsolation 39
UpgradeInProgress 40
IncompatibleAdminRxBbCredit 41
IncompatibleAdminRxBufferSize 42
PortChannelMembersDown 43
ZoneRemoteNoRespIsolation 44
FirstPortUpAsEport 45
FirstPortNotUp 46
PeerFCIPPortClosedConnection 47
PeerFCIPPortResetConnection 48
FcipPortMaxReTx 49
FcipPortKeepAliveTimerExpire 50
FcipPortPersistTimerExpire 51
FcipPortSrcLinkDown 52
FcipPortSrcAdminDown 53
FcipPortAdminCfgChange 54
FcipSrcPortRemoved 55
FcipSrcModuleNotOnline 56
InvalidConfig 57
PortBindFailure 58
PortFabricBindFailure 59
NoCommonVsanIsolation 60
FiconVsanDown 61
InvalidAttachment 62
PortBlocked 63
IncomAdminRxBbCreditPerBuf 64
TooManyInvalidFlogis 65
DeniedDueToPortBinding 66
ElpFailureRevMismatch 67
ElpFailureClassFParamErr 68
ElpFailureClassNParamErr 69
ElpFailureUnknownFlowCtlCode 70
ElpFailureInvalidFlowCtlParam 71
ElpFailureInvalidPortName 72
ElpFailureInvalidSwitchName 73
ElpFailureRatovEdtovMismatch 74
ElpFailureLoopbackDetected 75
ElpFailureInvalidTxBbCredit 76
ElpFailureInvalidPayloadSize 77
BundleMisCfg 78
BitErrRuntimeThreshExceeded 79
LinkFailLinkReset 80
LinkFailPortInitFail 81
LinkFailPortUnusable 82
LinkFailLossOfSignal 83
LinkFailLossOfSync 84
LinkFailNosRcvd 85
LinkFailOlsRcvd 86
LinkFailDebounceTimeout 87
LinkFailLrRcvd 88
LinkFailCreditLoss 89
LinkFailRxQOverflow 90
LinkFailTooManyInterrupts 91
LinkFailLipRcvdBb 92
LinkFailBbCreditLoss 93
LinkFailOpenPrimSignalTimeout 94
LinkFailOpenPrimSignalReturned 95
LinkFailLipF8Rcvd 96
LinkFailLineCardPortShutdown 97
FcspAuthenfailure 98
FcotChecksumError 99
InvalidFabricBindExchange 100
InvalidFabricBindExchange 101
TovMismatch 102
FiconNotEnabled 103
FiconNoPortNumber 104
FiconBeingEnabled 105
EPortProhibited 106
PortGracefulShutdown 107
TrunkNotFullyActive 108
FabricBindingSwitchWwnNotFound 109
FabricBindingDomainInvalid 110
FabricBindingDbMismatch 111
FabricBindingNoRspFromPeer 112

Note:

By default, this measure reports the Measure Values listed in the table above to indicate the current operation state of the network interface.. The graph of this measure however, represents the status of a server using the numeric equivalents only - 0 to 112.