IPWorks SNMP 2022 .NET Edition
Version 22.0 [Build 8369]

SNMPMgr Component

Properties   Methods   Events   Config Settings   Errors  

The SNMPMgr component is used to implement UDP-based SNMP Management Applications.

Syntax

nsoftware.IPWorksSNMP.Snmpmgr

Remarks

The SNMPMgr component implements a UDP-based standard SNMP Manager as specified in the SNMP RFCs. The component supports SNMP v1, v2c, and v3.

The component provides both encoding/decoding and transport capabilities, making the task of developing a custom SNMP manager as simple as setting a few key properties and handling a few events. SNMP data, such as for instance SNMP object id-s (OID-s) are exchanged as text strings, thus further simplifying the task of handling them.

The component is activated/deactivated by calling the Activate or Deactivate method. These methods enable or disable sending and receiving. The activation status can be found in the Active property.

Messages are received through events such as Response, Trap, or InformRequest. SNMP Traps are received through the Trap event.

Messages are sent to other agents or managers by using component's methods such as SendGetRequest, SendGetNextRequest, SendGetBulkRequest, SendSetRequest, and SendInformRequest.

SNMP OIDs, types, and values are provided in the Objects collection of SNMP objects for both sent and received packets.

SNMPv3 USM security is enabled by setting properties such as User, AuthenticationPassword, and EncryptionPassword and calling the Discover method to bind to a particular agent (RemoteEngineId). Upon successful discovery, received packets are checked for integrity (authentication) and timeliness. Note that the discovery step is optional, and may be avoided if the values for RemoteEngineId, RemoteEngineBoots, and RemoteEngineTime are known in advance and provided to the component through the respective properties.

By default, the component operates synchronously (except for the Discover method), sending a request and waiting until the corresponding response has been received. This behavior may be overridden by setting Timeout to 0, in which case the component returns control immediately after a send, and responses are received exclusively through the Response event.

Property List


The following is the full list of the properties of the component with short descriptions. Click on the links for further details.

AcceptDataEnables or disables data reception.
ActiveIndicates whether the component is active.
AuthenticationPasswordThe password used for SNMPv3 authentication.
AuthenticationProtocolThe authentication protocol used for SNMPv3 packets.
CommunityThe community string used to authenticate SNMP packets.
EncryptionAlgorithmThe encryption algorithm used for SNMPv3 packets.
EncryptionPasswordThe password used for SNMPv3 privacy.
ErrorDescriptionDescription of the status code for the last SNMP packet received by the component.
ErrorIndexIndex of the first variable (object) that caused an error from the last SNMP response.
ErrorStatusStatus code for the last SNMP packet received by the component.
LocalEngineIdThe Engine Id of the SNMP Manager.
LocalHostThe name of the local host or user-assigned IP interface through which connections are initiated or accepted.
LocalPortThe port in the local host where the SNMP Manager is bound to.
ObjectsThe objects in the current request.
RemoteEngineBootsThe remote engine boots (SNMPv3).
RemoteEngineIdThe Engine Id of the remote agent.
RemoteEngineTimeThe remote engine time (SNMPv3).
RemoteHostThe address of the remote host. Domain names are resolved to IP addresses.
RemotePortThe port where the remote SNMP agent is listening.
RequestIdThe request-id to mark outgoing packets with.
SNMPVersionVersion of SNMP used for outgoing requests.
StoreWalkObjectsTells the component whether or not to store returned objects.
TimeoutA timeout for the component.
UserThe user name used for SNMPv3 authentication.
WalkLimitThe limit of oid's returned in a walk.

Method List


The following is the full list of the methods of the component with short descriptions. Click on the links for further details.

ActivateActivates the component.
ConfigSets or retrieves a configuration setting.
DeactivateDeactivates the component.
DiscoverPerforms SNMPv3 discovery.
DoEventsProcesses events from the internal message queue.
HashPasswordsHashes all passwords in the cache.
InterruptInterrupt the current method.
ResetClears the object arrays.
SendGetBulkRequestSend a GetBulkRequest packet.
SendGetNextRequestSend GetNextRequest packet.
SendGetRequestSend GetRequest packet.
SendInformRequestSend an InformRequest packet.
SendSetRequestSend Set Request packet.
ValueReturns the value corresponding to an OID.
WalkDoes an SNMP walk starting with the specified oid.

Event List


The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.

BadPacketFired for erroneous and/or malformed messages.
DiscoveryRequestFired when an SNMPv3 discovery packet is received.
DiscoveryResponseFired when an SNMPv3 discovery response is received.
ErrorInformation about errors during data delivery.
HashPasswordFired before and after a password is hashed.
InformRequestFired when an InformRequest packet is received.
PacketTraceFired for every packet sent or received.
ReadyToSendFired when the component is ready to send data.
ReportFired when a Report packet is received.
ResponseFired when a GetResponse packet is received.
TrapFired when a SNMP trap packet is received.

Config Settings


The following is a list of config settings for the component with short descriptions. Click on the links for further details.

AllowSingleStepDiscoveryWhether to allow discovery to be completed in a single step.
CheckMessageOriginWhether to match the origin IP address when receiving responses.
CompatibilityModeWhether to operate the component in a specific compatibility mode.
ContextEngineIdSets the context engine id of the SNMP entity.
ContextNameSets the context name of the SNMP entity.
DecryptLogPacketsWhether to decrypt logged packets.
DerivedKeyCacheSizeThe size of the internal cache used to store derived keys.
DerivedKeyCacheStatusThe status of the internal cache used to store derived keys.
ForceLocalPortForces the component to bind to a specific port.
IgnorePortMismatchWhether to check if the port matches when a response is received.
MsgMaxSizeThe maximum supported message size.
SourceAddressThe source address of the received packet.
SourcePortThe source port of the received packet.
SynchronizeEventsControls whether or not events are fired from the main thread when timeout is positive.
TimeoutInMillisecondsThe timeout is treated as milliseconds.
WalkInsideRangeStops the SNMP walk if the OID value returned from an agent is outside the table.
WalkStartOIDSpecifies the OID to be used when a Walk is performed.
CaptureIPPacketInfoUsed to capture the packet information.
DelayHostResolutionWhether the hostname is resolved when RemoteHost is set.
DestinationAddressUsed to get the destination address from the packet information.
DontFragmentUsed to set the Don't Fragment flag of outgoing packets.
LocalHostThe name of the local host through which connections are initiated or accepted.
LocalPortThe port in the local host where the component binds.
MaxPacketSizeThe maximum length of the packets that can be received.
QOSDSCPValueUsed to specify an arbitrary QOS/DSCP setting (optional).
QOSTrafficTypeUsed to specify QOS/DSCP settings (optional).
ShareLocalPortIf set to True, allows more than one instance of the component to be active on the same local port.
UseConnectionDetermines whether to use a connected socket.
UseIPv6Whether or not to use IPv6.
AbsoluteTimeoutDetermines whether timeouts are inactivity timeouts or absolute timeouts.
FirewallDataUsed to send extra data to the firewall.
InBufferSizeThe size in bytes of the incoming queue of the socket.
OutBufferSizeThe size in bytes of the outgoing queue of the socket.
BuildInfoInformation about the product's build.
GUIAvailableTells the component whether or not a message loop is available for processing events.
LicenseInfoInformation about the current license.
UseInternalSecurityAPITells the component whether or not to use the system security libraries or an internal implementation.

AcceptData Property (SNMPMgr Component)

Enables or disables data reception.

Syntax

public bool AcceptData { get; set; }
Public Property AcceptData As Boolean

Default Value

True

Remarks

Setting the property to False temporarily disables data reception. Setting the property to True re-enables data reception.

This property is not available at design time.

Active Property (SNMPMgr Component)

Indicates whether the component is active.

Syntax

public bool Active { get; set; }
Public Property Active As Boolean

Default Value

False

Remarks

This property indicates whether the component is currently active and can send or receive data.

The component will be automatically activated if it is not already and you attempt to perform an operation which requires the component to be active.

Note: Use the Activate or Deactivate method to control whether the component is active.

This property is not available at design time.

AuthenticationPassword Property (SNMPMgr Component)

The password used for SNMPv3 authentication.

Syntax

public string AuthenticationPassword { get; set; }
Public Property AuthenticationPassword As String

Default Value

""

Remarks

Every time EncryptionPassword, AuthenticationPassword, or RemoteEngineId are set, a localized key is computed automatically, and cached internally.

AuthenticationProtocol Property (SNMPMgr Component)

The authentication protocol used for SNMPv3 packets.

Syntax

public SnmpmgrAuthenticationProtocols AuthenticationProtocol { get; set; }

enum SnmpmgrAuthenticationProtocols { authpHMACMD596, authpHMACSHA96, authpHMAC192SHA256, authpHMAC384SHA512 }
Public Property AuthenticationProtocol As SnmpmgrAuthenticationProtocols

Enum SnmpmgrAuthenticationProtocols authpHMACMD596 authpHMACSHA96 authpHMAC192SHA256 authpHMAC384SHA512 End Enum

Default Value

1

Remarks

This property defines the authentication protocol used when SNMPVersion is set to snmpverV3. Possible values are:

  • 1 (HMAC-MD5-96 - default)
  • 2 (HMAC-SHA-96)
  • 3 (HMAC-192-SHA-256)
  • 4 (HMAC-384-SHA-512)

This property is not available at design time.

Community Property (SNMPMgr Component)

The community string used to authenticate SNMP packets.

Syntax

public string Community { get; set; }
Public Property Community As String

Default Value

"public"

Remarks

Must match the community name that is specified on the agent.

Typical values are "public" or "private".

This property is used for all SNMP packets sent by the component.

EncryptionAlgorithm Property (SNMPMgr Component)

The encryption algorithm used for SNMPv3 packets.

Syntax

public SnmpmgrEncryptionAlgorithms EncryptionAlgorithm { get; set; }

enum SnmpmgrEncryptionAlgorithms { encraDES, encraAES, encra3DES, encraAES192, encraAES256 }
Public Property EncryptionAlgorithm As SnmpmgrEncryptionAlgorithms

Enum SnmpmgrEncryptionAlgorithms encraDES encraAES encra3DES encraAES192 encraAES256 End Enum

Default Value

1

Remarks

In order to use encryption, you must set the EncryptionPassword property. The supported algorithms for encryption are:

DES (1)Data Encryption Standard.
AES (2)Advanced Encryption Standard with key length of 128.
3DES (3)Triple Data Encryption Standard.
AES192 (4)Advanced Encryption Standard with key length of 192.
AES256 (5)Advanced Encryption Standard with key length of 256.

This property is not available at design time.

EncryptionPassword Property (SNMPMgr Component)

The password used for SNMPv3 privacy.

Syntax

public string EncryptionPassword { get; set; }
Public Property EncryptionPassword As String

Default Value

""

Remarks

Every time EncryptionPassword, AuthenticationPassword, or RemoteEngineId are set, a localized key is computed automatically, and cached internally.

ErrorDescription Property (SNMPMgr Component)

Description of the status code for the last SNMP packet received by the component.

Syntax

public string ErrorDescription { get; }
Public ReadOnly Property ErrorDescription As String

Default Value

"0"

Remarks

Please refer to the ErrorStatus property for more information.

This property is read-only and not available at design time.

ErrorIndex Property (SNMPMgr Component)

Index of the first variable (object) that caused an error from the last SNMP response.

Syntax

public int ErrorIndex { get; }
Public ReadOnly Property ErrorIndex As Integer

Default Value

0

Remarks

This property is used in conjunction with the ErrorStatus property, and refers to the object that caused the error reported in the last SNMP response. This value is parsed directly from the SNMP response, which will be a one-based value, so a value of i here maps to index i-1 in the Objects collection.

The ErrorIndex property has no meaning when the ErrorStatus property is 0 (no error).

This property is read-only and not available at design time.

ErrorStatus Property (SNMPMgr Component)

Status code for the last SNMP packet received by the component.

Syntax

public int ErrorStatus { get; }
Public ReadOnly Property ErrorStatus As Integer

Default Value

0

Remarks

This property is used in conjunction with the ErrorIndex property, which denotes the index of the variable in error. The ErrorDescription property provides a textual description of the error.

The following is a list of valid SNMP status code values:

0 (noError) No error.
1 (tooBig) The response cannot fit in a single SNMP message.
2 (noSuchName) Variable does not exist.
3 (badValue) Invalid value or syntax.
4 (readOnly) Variable is read-only.
5 (genError) Other error (SNMPv1).
6 (noAccess) Access denied.
7 (wrongType) Wrong object type.
8 (wrongLength) Wrong length.
9 (wrongEncoding) Wrong encoding.
10 (wrongValue) Wrong value.
11 (noCreation) No creation.
12 (inconsistentValue) Inconsistent value.
13 (resourceUnavailable) Resource unavailable.
14 (commitFailed) Commit failed.
15 (undoFailed) Undo failed.
16 (authorizationError) Authorization error.
17 (notWritable) Variable is not writable.
18 (inconsistentName) Inconsistent name.

The ErrorIndex parameter indicates the index of the first variable (object) that caused an error. The default value is 0.

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

The default value is 0 (no error).

This property is read-only and not available at design time.

LocalEngineId Property (SNMPMgr Component)

The Engine Id of the SNMP Manager.

Syntax

public string LocalEngineId { get; set; }
public byte[] LocalEngineIdB { get; set; }
Public Property LocalEngineId As String
Public Property LocalEngineIdB As Byte()

Default Value

""

Remarks

This property is only used for SNMPv3 packets (when SNMPVersion is 3).

LocalHost Property (SNMPMgr Component)

The name of the local host or user-assigned IP interface through which connections are initiated or accepted.

Syntax

public string LocalHost { get; set; }
Public Property LocalHost As String

Default Value

""

Remarks

The LocalHost property contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

If the component is connected, the LocalHost property shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

NOTE: LocalHost is not persistent. You must always set it in code, and never in the property window.

LocalPort Property (SNMPMgr Component)

The port in the local host where the SNMP Manager is bound to.

Syntax

public int LocalPort { get; set; }
Public Property LocalPort As Integer

Default Value

0

Remarks

The LocalPort property must be set before the component is activated (Active is set to True). It instructs the component to bind to a specific port (or communication endpoint) in the local machine. The default port is 0 (random port). If you would like to receive traps, set LocalPort to 162 (standard trap port). However, it is recommended that the SNMPTrapMgr component be used for listening to traps, because SNMPMgr is limited to receiving SNMPv3 traps from a single agent only. SNMPTrapMgr does not have this limitation.

LocalPort cannot be changed once the component is Active. Any attempt to set the LocalPort property when the component is Active will generate an error.

Note: on macOS and iOS, root permissions are required to set LocalPort to any value below 1024.

Objects Property (SNMPMgr Component)

The objects in the current request.

Syntax

public SNMPObjectList Objects { get; }
Public Property Objects As SNMPObjectList

Remarks

The SNMP objects being sent or received in the current request. The collection is first cleared, then populated every time an SNMP packet is received. It is also used to create outgoing SNMP packets.

This collection is indexed from 0 to count -1.

RemoteEngineBoots Property (SNMPMgr Component)

The remote engine boots (SNMPv3).

Syntax

public int RemoteEngineBoots { get; set; }
Public Property RemoteEngineBoots As Integer

Default Value

0

Remarks

This property is used in conjunction with the RemoteEngineTime property. Please refer to the description of the RemoteEngineTime property, and the Discover method for further information.

RemoteEngineId Property (SNMPMgr Component)

The Engine Id of the remote agent.

Syntax

public string RemoteEngineId { get; set; }
public byte[] RemoteEngineIdB { get; set; }
Public Property RemoteEngineId As String
Public Property RemoteEngineIdB As Byte()

Default Value

""

Remarks

This property is only used for SNMPv3 packets (see SNMPVersion), and is reset every time RemoteHost or RemotePort changes.

RemoteEngineId is normally discovered through the Discover method. However, by manually supplying a value for the property, RemoteEngineId discovery step may be eliminated, thus avoiding the extra roundtrip to the agent (RemoteEngineBoots and RemoteEngineTime are also required for User authentication - please refer to the Discover method for more information).

RemoteEngineTime Property (SNMPMgr Component)

The remote engine time (SNMPv3).

Syntax

public int RemoteEngineTime { get; set; }
Public Property RemoteEngineTime As Integer

Default Value

0

Remarks

RemoteEngineTime is used by SNMPv3 authentication to ensure timeliness of requests, and avoid replay attacks.

The value of RemoteEngineTime is provided as what is expected to be the current value of the remote engine clock based on a cached time differential between the remote engine clock and the local engine time obtained during the discovery process (see Discover).

This property is used in conjunction with RemoteEngineBoots. Please refer to the RemoteEngineBoots property and the Discover method for more information.

RemoteHost Property (SNMPMgr Component)

The address of the remote host. Domain names are resolved to IP addresses.

Syntax

public string RemoteHost { get; set; }
Public Property RemoteHost As String

Default Value

""

Remarks

The RemoteHost property specifies the IP address (IP number in dotted internet format) or Domain Name of the host SNMP requests or traps are sent to.

If RemoteHost is set to 255.255.255.255, the component broadcasts data on the local subnet.

If the RemoteHost property is set to a Domain Name, a DNS request is initiated and upon successful termination of the request, the RemoteHost property is set to the corresponding address. If the search is not successful, an error is returned.

RemotePort Property (SNMPMgr Component)

The port where the remote SNMP agent is listening.

Syntax

public int RemotePort { get; set; }
Public Property RemotePort As Integer

Default Value

161

Remarks

The RemotePort is the port on the RemoteHost to send SNMP requests to.

A valid port number (a value between 1 and 65535) is required. The default value is 161.

RequestId Property (SNMPMgr Component)

The request-id to mark outgoing packets with.

Syntax

public int RequestId { get; set; }
Public Property RequestId As Integer

Default Value

1

Remarks

If a custom value is needed for RequestId, the property must be set before sending the request. The component increments RequestId automatically after sending each packet.

This property is not available at design time.

SNMPVersion Property (SNMPMgr Component)

Version of SNMP used for outgoing requests.

Syntax

public SnmpmgrSNMPVersions SNMPVersion { get; set; }

enum SnmpmgrSNMPVersions { snmpverV1, snmpverV2c, snmpverV3 }
Public Property SNMPVersion As SnmpmgrSNMPVersions

Enum SnmpmgrSNMPVersions snmpverV1 snmpverV2c snmpverV3 End Enum

Default Value

2

Remarks

This property takes one of the following values:

snmpverV1 (1)SNMP Version 1.
snmpverV2c (2)SNMP Version 2c.
snmpverV3 (3)SNMP Version 3.

StoreWalkObjects Property (SNMPMgr Component)

Tells the component whether or not to store returned objects.

Syntax

public bool StoreWalkObjects { get; set; }
Public Property StoreWalkObjects As Boolean

Default Value

True

Remarks

When a Walk is performed, this property tells the component whether or not to store the objects that are returned by the server in the Objects collection. If the data is accumulated through the events, and not desired to be saved by the component, set this property to false.

Timeout Property (SNMPMgr Component)

A timeout for the component.

Syntax

public int Timeout { get; set; }
Public Property Timeout As Integer

Default Value

60

Remarks

If the Timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If Timeout is set to a positive value, data is sent in a blocking manner and the component will wait for the operation to complete before returning control. The component will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of Timeout seconds.

The component will use DoEvents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not "freeze" and remains responsive.

If Timeout expires, and the operation is not yet complete, the component throws an exception.

Please note that by default, all timeouts are inactivity timeouts, i.e. the timeout period is extended by Timeout seconds when any amount of data is successfully sent or received.

The default value for the Timeout property is 60 seconds.

User Property (SNMPMgr Component)

The user name used for SNMPv3 authentication.

Syntax

public string User { get; set; }
Public Property User As String

Default Value

""

Remarks

If authentication is desired, this property must be set before the component attempts to connect to an SNMPv3 Agent.

WalkLimit Property (SNMPMgr Component)

The limit of oid's returned in a walk.

Syntax

public int WalkLimit { get; set; }
Public Property WalkLimit As Integer

Default Value

0

Remarks

This property specifies the limit of how many oid's are to be traversed during an SNMP Walk. If set to 0, the component will traverse all oid's in the specified table that are lexographically greater than the value of the specified table oid.

Activate Method (SNMPMgr Component)

Activates the component.

Syntax

public void Activate();

Async Version
public async Task Activate();
public async Task Activate(CancellationToken cancellationToken);
Public Sub Activate()

Async Version
Public Sub Activate() As Task
Public Sub Activate(cancellationToken As CancellationToken) As Task

Remarks

This method activates the component and will allow it to send or receive data.

The component will be automatically activated if it is not already and you attempt to perform an operation which requires the component to be active.

Note: Use the Active property to check whether the component is active.

Config Method (SNMPMgr Component)

Sets or retrieves a configuration setting.

Syntax

public string Config(string configurationString);

Async Version
public async Task<string> Config(string configurationString);
public async Task<string> Config(string configurationString, CancellationToken cancellationToken);
Public Function Config(ByVal ConfigurationString As String) As String

Async Version
Public Function Config(ByVal ConfigurationString As String) As Task(Of String)
Public Function Config(ByVal ConfigurationString As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

Deactivate Method (SNMPMgr Component)

Deactivates the component.

Syntax

public void Deactivate();

Async Version
public async Task Deactivate();
public async Task Deactivate(CancellationToken cancellationToken);
Public Sub Deactivate()

Async Version
Public Sub Deactivate() As Task
Public Sub Deactivate(cancellationToken As CancellationToken) As Task

Remarks

This method deactivates the component and will prohibit it from sending and receiving data.

Note: Use the Active property to check whether the component is active.

Discover Method (SNMPMgr Component)

Performs SNMPv3 discovery.

Syntax

public void Discover();

Async Version
public async Task Discover();
public async Task Discover(CancellationToken cancellationToken);
Public Sub Discover()

Async Version
Public Sub Discover() As Task
Public Sub Discover(cancellationToken As CancellationToken) As Task

Remarks

When the method is called an SNMPv3 engine discovery request is sent to RemoteHost.

If an AuthenticationPassword is provided, the engine id discovery request is followed by an engine time discovery request, as required by the SNMPv3 User Security Model (USM). In this case Timeout must be set to a non-zero value before calling Discover and the component will wait until a response is received from RemoteHost.

The DiscoveryResponse event is fired upon receipt of a valid discovery response and the values of RemoteEngineId, RemoteEngineBoots, and RemoteEngineTime will then be updated with the received Engine Id, Time, and Boots.

DoEvents Method (SNMPMgr Component)

Processes events from the internal message queue.

Syntax

public void DoEvents();

Async Version
public async Task DoEvents();
public async Task DoEvents(CancellationToken cancellationToken);
Public Sub DoEvents()

Async Version
Public Sub DoEvents() As Task
Public Sub DoEvents(cancellationToken As CancellationToken) As Task

Remarks

When DoEvents is called, the component processes any available events. If no events are available, it waits for a preset period of time, and then returns.

HashPasswords Method (SNMPMgr Component)

Hashes all passwords in the cache.

Syntax

public void HashPasswords();

Async Version
public async Task HashPasswords();
public async Task HashPasswords(CancellationToken cancellationToken);
Public Sub HashPasswords()

Async Version
Public Sub HashPasswords() As Task
Public Sub HashPasswords(cancellationToken As CancellationToken) As Task

Remarks

Forces computation of all passwords hashes in the cache. Used together with the HashPassword event to enable implementations of external password hash storage.

Interrupt Method (SNMPMgr Component)

Interrupt the current method.

Syntax

public void Interrupt();

Async Version
public async Task Interrupt();
public async Task Interrupt(CancellationToken cancellationToken);
Public Sub Interrupt()

Async Version
Public Sub Interrupt() As Task
Public Sub Interrupt(cancellationToken As CancellationToken) As Task

Remarks

If there is no method in progress, Interrupt simply returns, doing nothing.

Reset Method (SNMPMgr Component)

Clears the object arrays.

Syntax

public void Reset();

Async Version
public async Task Reset();
public async Task Reset(CancellationToken cancellationToken);
Public Sub Reset()

Async Version
Public Sub Reset() As Task
Public Sub Reset(cancellationToken As CancellationToken) As Task

Remarks

Clears the object arrays, and sets the trap and error properties to their default values. This is useful for reinitializing all the properties that are used to create outgoing packets before building a new packet.

Note: SNMPVersion will be reset to snmpverV2c (2).

SendGetBulkRequest Method (SNMPMgr Component)

Send a GetBulkRequest packet.

Syntax

public void SendGetBulkRequest(int nonRepeaters, int maxRepetitions);

Async Version
public async Task SendGetBulkRequest(int nonRepeaters, int maxRepetitions);
public async Task SendGetBulkRequest(int nonRepeaters, int maxRepetitions, CancellationToken cancellationToken);
Public Sub SendGetBulkRequest(ByVal NonRepeaters As Integer, ByVal MaxRepetitions As Integer)

Async Version
Public Sub SendGetBulkRequest(ByVal NonRepeaters As Integer, ByVal MaxRepetitions As Integer) As Task
Public Sub SendGetBulkRequest(ByVal NonRepeaters As Integer, ByVal MaxRepetitions As Integer, cancellationToken As CancellationToken) As Task

Remarks

Sends a GetBulkRequest packet. This is only available for SNMP versions 2 and 3.

NonRepeaters specifies the number of variables for which a single lexicographic successor is to be returned.

MaxRepetitions specifies the number of lexicographic successors to be returned for variables other than those in the NonRepeaters list.

The object identifiers, types, and values for the request are taken from the Objects collection.

A GetBulkRequest is very similar to a GetNextRequest, the difference is that Getbulk performs a continuous GetNext operation based on the MaxRepitions value. The NonRepeaters value will determine the number of Objects for which a simple GetNext operation should be performed. For the remaining variables, a continuous GetNext operation is performed based on the MaxRepitions value.

So if you send a request containing X objects, the agent will perform N simple GetNext operations and M continuous GetNext operations X - N times. With X being the number of objects received, N being the number of NonRepeaters, and M being the number of MaxRepitions. Thus the SNMPMgr is expecting to receive N + M x (X - N) objects, assuming that each object has M successors.

Example (Sending a GetBulk Request)

SNMPControl.RemoteHost = "MyAgent" SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.1.0")) SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.3.0")) SNMPControl.SendGetBulkRequest(1,4)

The code sample above will send a GetBulkRequest with 1 non repeater, and a maxrepetitions of 4. Since there is only 1 non repeater, only one ObjID will "not repeat" and will only return one successor. The rest of the ObjID's (in this case, only 1) will return 4 successors. This particular example will return the following ObjID's:

1 1.3.6.1.2.1.1.2.0
2 1.3.6.1.2.1.1.4.0
3 1.3.6.1.2.1.1.5.0
4 1.3.6.1.2.1.1.6.0
5 1.3.6.1.2.1.1.7.0

SendGetNextRequest Method (SNMPMgr Component)

Send GetNextRequest packet.

Syntax

public void SendGetNextRequest();

Async Version
public async Task SendGetNextRequest();
public async Task SendGetNextRequest(CancellationToken cancellationToken);
Public Sub SendGetNextRequest()

Async Version
Public Sub SendGetNextRequest() As Task
Public Sub SendGetNextRequest(cancellationToken As CancellationToken) As Task

Remarks

Sends a GetNextRequest packet. The object identifiers, types, and values for the request are taken from the Objects collection.

Example (Sending a GetNext Request)

SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.1.0")) SNMPControl.SendGetNextRequest() The agent will respond with the "next" (relative to the ObjID(s) you specify) OID in the table.

SendGetRequest Method (SNMPMgr Component)

Send GetRequest packet.

Syntax

public void SendGetRequest();

Async Version
public async Task SendGetRequest();
public async Task SendGetRequest(CancellationToken cancellationToken);
Public Sub SendGetRequest()

Async Version
Public Sub SendGetRequest() As Task
Public Sub SendGetRequest(cancellationToken As CancellationToken) As Task

Remarks

Sends a GetRequest packet. The object identifiers, types, and values for the request are taken from the Objects collection.

Example (Sending a GetRequest)

SNMPControl.RemoteHost = "MyAgent" SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.1.0")) SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.2.0")) SNMPControl.SendGetRequest()

SendInformRequest Method (SNMPMgr Component)

Send an InformRequest packet.

Syntax

public void SendInformRequest();

Async Version
public async Task SendInformRequest();
public async Task SendInformRequest(CancellationToken cancellationToken);
Public Sub SendInformRequest()

Async Version
Public Sub SendInformRequest() As Task
Public Sub SendInformRequest(cancellationToken As CancellationToken) As Task

Remarks

Sends an InformRequest packet. The object identifiers, types, and values for the request are taken from the Objects collection.

SendSetRequest Method (SNMPMgr Component)

Send Set Request packet.

Syntax

public void SendSetRequest();

Async Version
public async Task SendSetRequest();
public async Task SendSetRequest(CancellationToken cancellationToken);
Public Sub SendSetRequest()

Async Version
Public Sub SendSetRequest() As Task
Public Sub SendSetRequest(cancellationToken As CancellationToken) As Task

Remarks

Sends a SetRequest packet. The object identifiers, types, and values for the request are taken from the Objects collection.

Example (Sending a SetRequest)

SNMPControl.RemoteHost = "MyAgent"; SNMPControl.Objects.Add(New SNMPObject("1.3.6.1.2.1.1.1.0")); SNMPControl.Objects[0].Value = "New Value"; SNMPControl.Objects[0].ObjectType = SNMPObjectTypes.otOctetString); SNMPControl.SendSetRequest();

Value Method (SNMPMgr Component)

Returns the value corresponding to an OID.

Syntax

public string Value(string OID);

Async Version
public async Task<string> Value(string OID);
public async Task<string> Value(string OID, CancellationToken cancellationToken);
Public Function Value(ByVal OID As String) As String

Async Version
Public Function Value(ByVal OID As String) As Task(Of String)
Public Function Value(ByVal OID As String, cancellationToken As CancellationToken) As Task(Of String)

Remarks

If the OID does not exist in the Objects collection, a trappable error is generated.

Please refer to the SNMPObject type for more information.

Walk Method (SNMPMgr Component)

Does an SNMP walk starting with the specified oid.

Syntax

public void Walk(string tableOid);

Async Version
public async Task Walk(string tableOid);
public async Task Walk(string tableOid, CancellationToken cancellationToken);
Public Sub Walk(ByVal TableOid As String)

Async Version
Public Sub Walk(ByVal TableOid As String) As Task
Public Sub Walk(ByVal TableOid As String, cancellationToken As CancellationToken) As Task

Remarks

A walk will traverse all OIDs in the TableOid that are lexographically greater than the value of the TableOid.

The results of the walk may be obtained through the Response events. During the event, the current returned object will exist inside of the Objects collection. If StoreWalkObjects is set to true, the Objects collection will contain all returned objects when the Walk completes.

Use the WalkLimit property to regulate how many objects the walk will traverse in the table.

NOTE: The collection of objects is cleared before the walk begins.

BadPacket Event (SNMPMgr Component)

Fired for erroneous and/or malformed messages.

Syntax

public event OnBadPacketHandler OnBadPacket;

public delegate void OnBadPacketHandler(object sender, SnmpmgrBadPacketEventArgs e);

public class SnmpmgrBadPacketEventArgs : EventArgs {
  public string Packet { get; }
public byte[] PacketB { get; } public string SourceAddress { get; } public int SourcePort { get; } public int ErrorCode { get; } public string ErrorDescription { get; } public bool Report { get; set; } }
Public Event OnBadPacket As OnBadPacketHandler

Public Delegate Sub OnBadPacketHandler(sender As Object, e As SnmpmgrBadPacketEventArgs)

Public Class SnmpmgrBadPacketEventArgs Inherits EventArgs
  Public ReadOnly Property Packet As String
Public ReadOnly Property PacketB As Byte() Public ReadOnly Property SourceAddress As String Public ReadOnly Property SourcePort As Integer Public ReadOnly Property ErrorCode As Integer Public ReadOnly Property ErrorDescription As String Public Property Report As Boolean End Class

Remarks

The full message is provided in the Packet parameter.

The BadPacket event is also fired when authentication fails for received packets due to a bad password or other reasons.

If the Report parameter is set to True, an unauthenticated error report will be sent to the client, otherwise the packet will be silently ignored.

DiscoveryRequest Event (SNMPMgr Component)

Fired when an SNMPv3 discovery packet is received.

Syntax

public event OnDiscoveryRequestHandler OnDiscoveryRequest;

public delegate void OnDiscoveryRequestHandler(object sender, SnmpmgrDiscoveryRequestEventArgs e);

public class SnmpmgrDiscoveryRequestEventArgs : EventArgs {
  public string EngineId { get; }
public byte[] EngineIdB { get; } public int EngineBoots { get; } public int EngineTime { get; } public string User { get; } public int SecurityLevel { get; } public string SourceAddress { get; } public int SourcePort { get; } public bool Respond { get; set; } }
Public Event OnDiscoveryRequest As OnDiscoveryRequestHandler

Public Delegate Sub OnDiscoveryRequestHandler(sender As Object, e As SnmpmgrDiscoveryRequestEventArgs)

Public Class SnmpmgrDiscoveryRequestEventArgs Inherits EventArgs
  Public ReadOnly Property EngineId As String
Public ReadOnly Property EngineIdB As Byte() Public ReadOnly Property EngineBoots As Integer Public ReadOnly Property EngineTime As Integer Public ReadOnly Property User As String Public ReadOnly Property SecurityLevel As Integer Public ReadOnly Property SourceAddress As String Public ReadOnly Property SourcePort As Integer Public Property Respond As Boolean End Class

Remarks

EngineId, EngineBoots, EngineTime, and User are the values received from SourceAddress.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

Respond is True by default, and will automatically send a response using the value in LocalEngineId. To suppress the response, set Respond to False.

The value returned to SourceAddress for EngineBoots is always 0, and EngineTime is the number of seconds since January 1st, 1970 (GMT).

DiscoveryResponse Event (SNMPMgr Component)

Fired when an SNMPv3 discovery response is received.

Syntax

public event OnDiscoveryResponseHandler OnDiscoveryResponse;

public delegate void OnDiscoveryResponseHandler(object sender, SnmpmgrDiscoveryResponseEventArgs e);

public class SnmpmgrDiscoveryResponseEventArgs : EventArgs {
  public string EngineId { get; }
public byte[] EngineIdB { get; } public int EngineBoots { get; } public int EngineTime { get; } public string User { get; } public int SecurityLevel { get; } public string SourceAddress { get; } public int SourcePort { get; } }
Public Event OnDiscoveryResponse As OnDiscoveryResponseHandler

Public Delegate Sub OnDiscoveryResponseHandler(sender As Object, e As SnmpmgrDiscoveryResponseEventArgs)

Public Class SnmpmgrDiscoveryResponseEventArgs Inherits EventArgs
  Public ReadOnly Property EngineId As String
Public ReadOnly Property EngineIdB As Byte() Public ReadOnly Property EngineBoots As Integer Public ReadOnly Property EngineTime As Integer Public ReadOnly Property User As String Public ReadOnly Property SecurityLevel As Integer Public ReadOnly Property SourceAddress As String Public ReadOnly Property SourcePort As Integer End Class

Remarks

EngineId, EngineBoots, EngineTime, and User are the values received from SourceAddress and SourcePort.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated request, SecurityLevel is at least 1.

Error Event (SNMPMgr Component)

Information about errors during data delivery.

Syntax

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, SnmpmgrErrorEventArgs e);

public class SnmpmgrErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}
Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As SnmpmgrErrorEventArgs)

Public Class SnmpmgrErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the component throws an exception.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

HashPassword Event (SNMPMgr Component)

Fired before and after a password is hashed.

Syntax

public event OnHashPasswordHandler OnHashPassword;

public delegate void OnHashPasswordHandler(object sender, SnmpmgrHashPasswordEventArgs e);

public class SnmpmgrHashPasswordEventArgs : EventArgs {
  public string Password { get; }
  public int AuthAlgorithm { get; }
  public string Hash { get; set; }
}
Public Event OnHashPassword As OnHashPasswordHandler

Public Delegate Sub OnHashPasswordHandler(sender As Object, e As SnmpmgrHashPasswordEventArgs)

Public Class SnmpmgrHashPasswordEventArgs Inherits EventArgs
  Public ReadOnly Property Password As String
  Public ReadOnly Property AuthAlgorithm As Integer
  Public Property Hash As String
End Class

Remarks

SNMPv3 passwords are hashed in order to obtain authentication and encryption keys. This is an expensive operation, and in certain situations it may be preferable to store the hashed passwords externally and supply them on demand.

If a hash is required, the event fires with an empty string in the Hash parameter. In this case, you can choose to supply a value for the hash and stop the component from computing the hash.

The event also fires every time a hash is computed. In this case, the Hash parameter contains the value of the computed hash.

AuthAlgorithm contains either 1 for HMAC-MD5-96, 2 for HMAC-SHA-96 or 3 for HMAC-192-SHA-256

InformRequest Event (SNMPMgr Component)

Fired when an InformRequest packet is received.

Syntax

public event OnInformRequestHandler OnInformRequest;

public delegate void OnInformRequestHandler(object sender, SnmpmgrInformRequestEventArgs e);

public class SnmpmgrInformRequestEventArgs : EventArgs {
  public int RequestId { get; }
  public int SNMPVersion { get; }
  public string Community { get; }
  public string User { get; }
  public int SecurityLevel { get; }
  public string SourceAddress { get; }
  public int SourcePort { get; }
  public int ErrorIndex { get; set; }
  public int ErrorStatus { get; set; }
  public string ErrorDescription { get; }
  public bool Respond { get; set; }
}
Public Event OnInformRequest As OnInformRequestHandler

Public Delegate Sub OnInformRequestHandler(sender As Object, e As SnmpmgrInformRequestEventArgs)

Public Class SnmpmgrInformRequestEventArgs Inherits EventArgs
  Public ReadOnly Property RequestId As Integer
  Public ReadOnly Property SNMPVersion As Integer
  Public ReadOnly Property Community As String
  Public ReadOnly Property User As String
  Public ReadOnly Property SecurityLevel As Integer
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
  Public Property ErrorIndex As Integer
  Public Property ErrorStatus As Integer
  Public ReadOnly Property ErrorDescription As String
  Public Property Respond As Boolean
End Class

Remarks

The user in an InformRequest packet (SNMPv3) must match the user in the User property. If not, the request is rejected, and a BadPacket event is fired before InformRequest is fired.

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

The MessageId parameter identifies the received request.

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

To send a response, the Respond parameter must be set to true. By default, this value is false, which means no response will be sent. The ErrorStatus parameter may also be set to a valid SNMP status code (the default value is 0, which represents no error).

The following is a list of valid SNMP status code values:

0 (noError) No error.
1 (tooBig) The response cannot fit in a single SNMP message.
2 (noSuchName) Variable does not exist.
3 (badValue) Invalid value or syntax.
4 (readOnly) Variable is read-only.
5 (genError) Other error (SNMPv1).
6 (noAccess) Access denied.
7 (wrongType) Wrong object type.
8 (wrongLength) Wrong length.
9 (wrongEncoding) Wrong encoding.
10 (wrongValue) Wrong value.
11 (noCreation) No creation.
12 (inconsistentValue) Inconsistent value.
13 (resourceUnavailable) Resource unavailable.
14 (commitFailed) Commit failed.
15 (undoFailed) Undo failed.
16 (authorizationError) Authorization error.
17 (notWritable) Variable is not writable.
18 (inconsistentName) Inconsistent name.

The ErrorIndex parameter indicates the index of the first variable (object) that caused an error. The default value is 0.

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

PacketTrace Event (SNMPMgr Component)

Fired for every packet sent or received.

Syntax

public event OnPacketTraceHandler OnPacketTrace;

public delegate void OnPacketTraceHandler(object sender, SnmpmgrPacketTraceEventArgs e);

public class SnmpmgrPacketTraceEventArgs : EventArgs {
  public string Packet { get; }
public byte[] PacketB { get; } public int Direction { get; } public string PacketAddress { get; } public int PacketPort { get; } }
Public Event OnPacketTrace As OnPacketTraceHandler

Public Delegate Sub OnPacketTraceHandler(sender As Object, e As SnmpmgrPacketTraceEventArgs)

Public Class SnmpmgrPacketTraceEventArgs Inherits EventArgs
  Public ReadOnly Property Packet As String
Public ReadOnly Property PacketB As Byte() Public ReadOnly Property Direction As Integer Public ReadOnly Property PacketAddress As String Public ReadOnly Property PacketPort As Integer End Class

Remarks

The PacketTrace event shows all the packets sent or received by the component.

Packet contains the full contents of the datagram.

Direction shows the direction of the packet: 1 for incoming packets, and 2 for outgoing packets.

In the case of an incoming packet, PacketAddress and PacketPort identify the source of the packet.

In the case of an outgoing packet, PacketAddress and PacketPort identify the destination of the packet.

ReadyToSend Event (SNMPMgr Component)

Fired when the component is ready to send data.

Syntax

public event OnReadyToSendHandler OnReadyToSend;

public delegate void OnReadyToSendHandler(object sender, SnmpmgrReadyToSendEventArgs e);

public class SnmpmgrReadyToSendEventArgs : EventArgs {
}
Public Event OnReadyToSend As OnReadyToSendHandler

Public Delegate Sub OnReadyToSendHandler(sender As Object, e As SnmpmgrReadyToSendEventArgs)

Public Class SnmpmgrReadyToSendEventArgs Inherits EventArgs
End Class

Remarks

The ReadyToSend event indicates that the underlying TCP/IP subsystem is ready to accept data after a failed DataToSend.

Report Event (SNMPMgr Component)

Fired when a Report packet is received.

Syntax

public event OnReportHandler OnReport;

public delegate void OnReportHandler(object sender, SnmpmgrReportEventArgs e);

public class SnmpmgrReportEventArgs : EventArgs {
  public int RequestId { get; }
  public int SNMPVersion { get; }
  public string Community { get; }
  public string User { get; }
  public int SecurityLevel { get; }
  public string SourceAddress { get; }
  public int SourcePort { get; }
  public int ErrorIndex { get; }
  public int ErrorStatus { get; }
  public string ErrorDescription { get; }
}
Public Event OnReport As OnReportHandler

Public Delegate Sub OnReportHandler(sender As Object, e As SnmpmgrReportEventArgs)

Public Class SnmpmgrReportEventArgs Inherits EventArgs
  Public ReadOnly Property RequestId As Integer
  Public ReadOnly Property SNMPVersion As Integer
  Public ReadOnly Property Community As String
  Public ReadOnly Property User As String
  Public ReadOnly Property SecurityLevel As Integer
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
  Public ReadOnly Property ErrorIndex As Integer
  Public ReadOnly Property ErrorStatus As Integer
  Public ReadOnly Property ErrorDescription As String
End Class

Remarks

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

Response Event (SNMPMgr Component)

Fired when a GetResponse packet is received.

Syntax

public event OnResponseHandler OnResponse;

public delegate void OnResponseHandler(object sender, SnmpmgrResponseEventArgs e);

public class SnmpmgrResponseEventArgs : EventArgs {
  public int RequestId { get; }
  public int SNMPVersion { get; }
  public string Community { get; }
  public string User { get; }
  public int SecurityLevel { get; }
  public string SourceAddress { get; }
  public int SourcePort { get; }
  public int ErrorIndex { get; }
  public int ErrorStatus { get; }
  public string ErrorDescription { get; }
}
Public Event OnResponse As OnResponseHandler

Public Delegate Sub OnResponseHandler(sender As Object, e As SnmpmgrResponseEventArgs)

Public Class SnmpmgrResponseEventArgs Inherits EventArgs
  Public ReadOnly Property RequestId As Integer
  Public ReadOnly Property SNMPVersion As Integer
  Public ReadOnly Property Community As String
  Public ReadOnly Property User As String
  Public ReadOnly Property SecurityLevel As Integer
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
  Public ReadOnly Property ErrorIndex As Integer
  Public ReadOnly Property ErrorStatus As Integer
  Public ReadOnly Property ErrorDescription As String
End Class

Remarks

The ErrorStatus and ErrorIndex parameters contain information about possible errors. ErrorDescription is a textual description of ErrorStatus. This value is parsed directly from the SNMP response, which will be a one-based value, so a value of i here maps to index i-1 in the Objects collection.

The following is a list of valid SNMP status code values:

0 (noError) No error.
1 (tooBig) The response cannot fit in a single SNMP message.
2 (noSuchName) Variable does not exist.
3 (badValue) Invalid value or syntax.
4 (readOnly) Variable is read-only.
5 (genError) Other error (SNMPv1).
6 (noAccess) Access denied.
7 (wrongType) Wrong object type.
8 (wrongLength) Wrong length.
9 (wrongEncoding) Wrong encoding.
10 (wrongValue) Wrong value.
11 (noCreation) No creation.
12 (inconsistentValue) Inconsistent value.
13 (resourceUnavailable) Resource unavailable.
14 (commitFailed) Commit failed.
15 (undoFailed) Undo failed.
16 (authorizationError) Authorization error.
17 (notWritable) Variable is not writable.
18 (inconsistentName) Inconsistent name.

The ErrorIndex parameter indicates the index of the first variable (object) that caused an error. The default value is 0.

Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

Trap Event (SNMPMgr Component)

Fired when a SNMP trap packet is received.

Syntax

public event OnTrapHandler OnTrap;

public delegate void OnTrapHandler(object sender, SnmpmgrTrapEventArgs e);

public class SnmpmgrTrapEventArgs : EventArgs {
  public int RequestId { get; }
  public int SNMPVersion { get; }
  public string Community { get; }
  public string User { get; }
  public int SecurityLevel { get; }
  public string TrapOID { get; }
  public long TimeStamp { get; }
  public string SourceAddress { get; }
  public int SourcePort { get; }
}
Public Event OnTrap As OnTrapHandler

Public Delegate Sub OnTrapHandler(sender As Object, e As SnmpmgrTrapEventArgs)

Public Class SnmpmgrTrapEventArgs Inherits EventArgs
  Public ReadOnly Property RequestId As Integer
  Public ReadOnly Property SNMPVersion As Integer
  Public ReadOnly Property Community As String
  Public ReadOnly Property User As String
  Public ReadOnly Property SecurityLevel As Integer
  Public ReadOnly Property TrapOID As String
  Public ReadOnly Property TimeStamp As Long
  Public ReadOnly Property SourceAddress As String
  Public ReadOnly Property SourcePort As Integer
End Class

Remarks

The SNMPTrapMgr component should normally be used to receive traps, since it was designed and contains functionality specifically for that purpose. The SNMPMgr component can only receive traps from the agent that it is has most recently discovered with the Discover method.

The TrapOID and TimeStamp parameters contain the Trap OID and TimeStamp. In the case of an SNMPv1 trap, there are two possible scenarios:

First, if the enterprise of the trap is "1.3.6.1.6.3.1.1.5", TrapOID will be a concatenation of TrapEnterprise and GenericTrap + 1. For instance a TrapOID of "1.3.6.1.6.3.1.1.5.5" has a TrapEnterprise of "1.3.6.1.6.3.1.1.5" and a GenericTrap of "4".

Second, In all other cases TrapOID will be a concatenation of the values for TrapEnterprise, GenericTrap, and SpecificTrap, separated by '.'.

For SNMPv2 and above, they are read from the variable-value list (if available).

For SNMPv3, the User parameter shows the user that was supplied with the packet. This parameter MUST be used together with the SecurityLevel parameter which shows the level of security in the message.

The SecurityLevel parameter shows whether the request has been authenticated. If SecurityLevel is 0, the request has NOT been authenticated (i.e. the packet signature has not been verified). For an authenticated, non encrypted request, SecurityLevel is 1. For an authenticated and encrypted request, SecurityLevel is 2.

The SNMPMgr component is limited to accepting authenticated traps only for the user specified in User and Password and from the engine specified in RemoteEngineId with time parameters in RemoteEngineBoots and RemoteEngineTime (usually this is the SNMP engine discovered through the last call to Discover). If authenticated traps come from a different engine, or for a different user, they are ignored, and a BadPacket event is fired instead.

The list of variables in the SNMP packet, including optional values and types, is provided through the Objects collection. Each object is of type SNMPObject. This type describes the Oid, ObjectType, and Value of each SNMP object. These variables must be copied to another location before the event has completed executing, or they may be overridden by other events.

The SourceAddress and SourcePort parameters show the address and port of the sender as reported by the TCP/IP stack.

SNMPObject Type

The current SNMP object.

Remarks

This type defines an SNMP object. Each object has an Oid, ObjectType, and Value. These values are populated by the component when incoming packets are received. You may use these fields to define objects to be used in outgoing packets.

Fields

ObjectType
SNMPObjectTypes

The current object's type. The default type is NULL (5).

The corresponding object id and value are specified by the Oid and Value fields.

Possible object type values include:

otInteger (2) 2
otOctetString (4) 4
otNull (5) 5
otObjectID (6) 6
otIPAddress (64)64
otCounter32 (65)65
otGauge32 (66)66
otTimeTicks (67)67
otOpaque (68)68
otNSAP (69)69
otCounter64 (70)70
otUnsignedInteger32 (71)71

The component also supports the following artificial object values used to designate error conditions:

otNoSuchObject (128)No such object error.
otNoSuchInstance (129)No such instance error.
otEndOfMibView (130)End of MIB View error.

Oid
String

The current object's id which is encoded as a string of numbers separated by periods. For instance: "1.3.6.1.2.1.1.1.0" (OID for "system description").

The corresponding object type and value (if any) are specified by the ObjectType and Value fields.

Example

SNMPControl.Objects.Add(new SNMPObject()) SNMPControl.Objects(0).Oid = "1.3.6.1.2.1.1.1.0"

TypeString
String

A string representation of the current object's ObjectType.

The corresponding object id and value are specified by the Oid and Value fields.

Value
String

The current object's value. The corresponding object id and type are specified by the Oid and ObjectType fields.

Example

SNMPControl.Objects.Add(new SNMPObject()) SNMPControl.Objects(0).Oid = "1.3.6.1.2.1.1.1.0" SNMPControl.Objects(0).Value = "New Value"

ValueB
Byte []

The current object's value. The corresponding object id and type are specified by the Oid and ObjectType fields.

Example

SNMPControl.Objects.Add(new SNMPObject()) SNMPControl.Objects(0).Oid = "1.3.6.1.2.1.1.1.0" SNMPControl.Objects(0).Value = "New Value"

Constructors

public SNMPObject();
Public SNMPObject()
public SNMPObject( oid);
Public SNMPObject(ByVal Oid As )
public SNMPObject( oid,  value);
Public SNMPObject(ByVal Oid As , ByVal Value As Byte())
public SNMPObject( oid,  value,  SNMPObjectType);
Public SNMPObject(ByVal Oid As , ByVal Value As Byte(), ByVal SNMPObjectType As )

Config Settings (SNMPMgr Component)

The component accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

SNMPManager Config Settings

AllowSingleStepDiscovery:   Whether to allow discovery to be completed in a single step.

When making a discovery request in SNMPv3 while this setting is set to False (default), the component will send a second discovery request even if the agent responds to the first request with the EngineBoots and EngineTime. If set to True, the component will skip the second request if all the necessary information is returned in the first response.

CheckMessageOrigin:   Whether to match the origin IP address when receiving responses.

This setting specifies whether the component matches the source IP address in the response to the destination IP address of the request. When True (default) the component makes sure that response are received from the same IP to which the request was sent. In most cases this does not need to be changed. If there is a specific reason that responses are expected to originate from a different IP from that which the request was sent, this may be set to False. When False the component will not check the origin of received responses.

CompatibilityMode:   Whether to operate the component in a specific compatibility mode.

This setting will cause the component to operate in a manner different than normal so that it is compatible with third-party products and libraries. The following table lists the possible values for this setting:

0 (default)Component operates normally for greatest compatibility.
1Component uses SNMP4j-compatible encryption (AES192 and AES256).

ContextEngineId:   Sets the context engine id of the SNMP entity.

If set, the context engine id included in the PDU will be set.

ContextName:   Sets the context name of the SNMP entity.

If set, the context name included in the PDU will be set.

DecryptLogPackets:   Whether to decrypt logged packets.

When set to true this setting will cause the component to decrypt packets logged in PacketTrace. This only applies when using SNMP Version 3. The default is false.

DerivedKeyCacheSize:   The size of the internal cache used to store derived keys.

When set to a value greater than 0 the component will cache keys derived from passwords. This can improve performance in some scenarios. This value should be set to twice the number of expected unique passwords (e.g. 20 for 10 passwords). This only applies when using SNMP Version 3.

The cache is enabled by default and the default value is 20. To disable the cache set the value to 0. This setting is only applicable when SNMPVersion is set to 3.

DerivedKeyCacheStatus:   The status of the internal cache used to store derived keys.

When queried this setting returns the number of slots occupied in the cache (e.g. 6/20). This setting only applies when SNMPVersion is set to 3.

ForceLocalPort:   Forces the component to bind to a specific port.

The default value is True, which makes the component throw an error if LocalPort is busy. When ForceLocalPort is set to False and the port is busy, the component silently chooses another random port.

IgnorePortMismatch:   Whether to check if the port matches when a response is received.

When a response is received, the component will validate that the port in the response is the same as the port in the request. To disable this, set this to True.

MsgMaxSize:   The maximum supported message size.

This setting specifies the maximum supported message size in bytes. This is only applicable when SNMPVersion is set to 3. This corresponds to the "msgMaxSize" field in the request.

SourceAddress:   The source address of the received packet.

This setting holds the source address of the received packet. This may be queried at any time, including from within an event, and returns the source address of the received packet. This value is read-only.

SourcePort:   The source port of the received packet.

This setting holds the source port of the received packet. This may be queried at any time, including from within an event, and returns the source port of the received packet. This value is read-only.

SynchronizeEvents:   Controls whether or not events are fired from the main thread when timeout is positive.

The default value is True, which makes the component fire events from the main thread when timeout is greater than zero. Note: If your application requires more speed and efficiency, or does not require events to be fired from the main thread, you can set this to False to fire the events from secondary threads. This config is not applicable if timeout is zero, when events will always be fired from secondary threads.

TimeoutInMilliseconds:   The timeout is treated as milliseconds.

Setting TimeoutInMilliseconds to true causes the component to use the value in Timeout as milliseconds instead of seconds, which is the default.

WalkInsideRange:   Stops the SNMP walk if the OID value returned from an agent is outside the table.

When WalkInsideRange is set to true the Walk will continue only while the OID Values returned from the agent are greater than the current OID Value. If an object is returned with an OID value that is out of this range it is not added to the Objects collection, the Error event will fire, and Walk will return. The default value is true.

WalkStartOID:   Specifies the OID to be used when a Walk is performed.

When this property is set and Walk is called, the first request sent will contain the specified WalkStartOID value. This feature is particularly useful in the case of errors, such as timeouts, that may occur during a Walk. In such a case, you can set WalkStartOID to the last OID returned before the Timeout occurred then call Walk again (using the original tableOID parameter value). This will allow you to continue the Walk where it left off (when the Timeout error occurred).

Note that when StoreWalkObjects is set to true and WalkStartOID is set, the existing entries in Objects will be maintained when Walk is called and new returned objects will be added (just as if no error occurred in the initial Walk call).

UDP Config Settings

CaptureIPPacketInfo:   Used to capture the packet information.

If this is set to true, the component will capture the IP packet information.

The default value for this setting is False.

Note: This setting is only available in Windows.

DelayHostResolution:   Whether the hostname is resolved when RemoteHost is set.

This setting specifies whether a hostname is resolved immediately when RemoteHost is set. If true the component will resolve the hostname and the IP address will be present in the RemoteHost property. If false, the hostname is not resolved until needed by the component when a method to connect or send data is called. If desired, ResolveRemoteHost may called to manually resolve the value in RemoteHost at any time.

The default value is false for the default library and true for the Async library. The default value is false.

DestinationAddress:   Used to get the destination address from the packet information.

If CaptureIPPacketInfo is set to true, then this will be populated with the packet's destination address when a packet is received. This information will be accessible in the DataIn event.

Note: This setting is only available in Windows.

DontFragment:   Used to set the Don't Fragment flag of outgoing packets.

When set to True, packets sent by the component will have the Don't Fragment flag set. The default value is False.

LocalHost:   The name of the local host through which connections are initiated or accepted.

The LocalHost setting contains the name of the local host as obtained by the gethostname() system call, or if the user has assigned an IP address, the value of that address.

In multi-homed hosts (machines with more than one IP interface) setting LocalHost to the value of an interface will make the component initiate connections (or accept in the case of server components) only through that interface.

If the component is connected, the LocalHost setting shows the IP address of the interface through which the connection is made in internet dotted format (aaa.bbb.ccc.ddd). In most cases, this is the address of the local host, except for multi-homed hosts (machines with more than one IP interface).

LocalPort:   The port in the local host where the component binds.

This must be set before a connection is attempted. It instructs the component to bind to a specific port (or communication endpoint) in the local machine.

Setting this to 0 (default) enables the system to choose a port at random. The chosen port will be shown by LocalPort after the connection is established.

LocalPort cannot be changed once a connection is made. Any attempt to set this when a connection is active will generate an error.

This; setting is useful when trying to connect to services that require a trusted port in the client side. An example is the remote shell (rsh) service in UNIX systems.

MaxPacketSize:   The maximum length of the packets that can be received.

This setting specifies the maximum size of the datagrams that the component will accept without truncation.

QOSDSCPValue:   Used to specify an arbitrary QOS/DSCP setting (optional).

UseConnection must be True to use this setting. This option allows you to specify an arbitrary DSCP value between 0 and 63. The default is 0. When set to the default value the component will not set a DSCP value.

Note: This setting uses the qWAVE API is only available on Windows 7, Windows Server 2008 R2, and later.

QOSTrafficType:   Used to specify QOS/DSCP settings (optional).

UseConnection must be True to use this setting. You may specify either the text or integer values: BestEffort (0), Background (1), ExcellentEffort (2), AudioVideo (3), Voice (4), and Control (5).

Note: This setting uses the qWAVE API which is only available on Windows Vista and Windows Server 2008 or above.

Note: QOSTrafficType must be set before setting Active to true.

ShareLocalPort:   If set to True, allows more than one instance of the component to be active on the same local port.

This option must be set before the component is activated through the Active property or it will have no effect.

The default value for this setting is False.

UseConnection:   Determines whether to use a connected socket.

UseConnection specifies whether the component should use a connected socket or not. The connection is defined as an association in between the local address/port and the remote address/port. As such, this is not a connection in the traditional TCP sense. What it means is only that the component will send and receive data only to and from the specified destination.

The default value for this setting is False.

UseIPv6:   Whether or not to use IPv6.

By default, the component expects an IPv4 address for local and remote host properties, and will create an IPv4 socket. To use IPv6 instead, set this to True.

Socket Config Settings

AbsoluteTimeout:   Determines whether timeouts are inactivity timeouts or absolute timeouts.

If AbsoluteTimeout is set to True, any method which does not complete within Timeout seconds will be aborted. By default, AbsoluteTimeout is False, and the timeout is an inactivity timeout.

Note: This option is not valid for UDP ports.

FirewallData:   Used to send extra data to the firewall.

When the firewall is a tunneling proxy, use this property to send custom (additional) headers to the firewall (e.g. headers for custom authentication schemes).

InBufferSize:   The size in bytes of the incoming queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be receiving. Increasing the value of the InBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the InBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

OutBufferSize:   The size in bytes of the outgoing queue of the socket.

This is the size of an internal queue in the TCP/IP stack. You can increase or decrease its size depending on the amount of data that you will be sending. Increasing the value of the OutBufferSize setting can provide significant improvements in performance in some cases.

Some TCP/IP implementations do not support variable buffer sizes. If that is the case, when the component is activated the OutBufferSize reverts to its defined size. The same happens if you attempt to make it too large or too small.

Base Config Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

GUIAvailable:   Tells the component whether or not a message loop is available for processing events.

In a GUI-based application, long-running blocking operations may cause the application to stop responding to input until the operation returns. The component will attempt to discover whether or not the application has a message loop and, if one is discovered, it will process events in that message loop during any such blocking operation.

In some non-GUI applications, an invalid message loop may be discovered that will result in errant behavior. In these cases, setting GUIAvailable to false will ensure that the component does not attempt to process external events.

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a component is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
UseInternalSecurityAPI:   Tells the component whether or not to use the system security libraries or an internal implementation.

By default the component will use the system security libraries to perform cryptographic functions where applicable. When set to false calls to unmanaged code will be made. In certain environments this is not desirable. To use a completely managed security implementation set this setting to true. Setting this to true tells the component to use the internal implementation instead of using the system's security API.

Note: This setting is static. The value set is applicable to all components used in the application.

When this value is set the product's system DLL is no longer required as a reference, as all unmanaged code is stored in that file.

Trappable Errors (SNMPMgr Component)

SNMPMgr Errors

201   Timeout.
301   Bad Object Index when accessing the Obj* properties. Timeout when performing an operation. Check the error description for details.
302   Value exceeds maximum number of objects allowed.
303   The value must be an IP address in dotted format.
305   Unsupported SNMP version.
306   Unknown PDU type.
307   The component is busy performing the current action.
308   Verification failed.
309   Missing password for Verification.
310   Missing signature.
311   Missing remote time.
312   Missing timeout value.
313   Decryption Failed.
314   Missing password for decryption.
315   Not encrypted.
316   Security model not supported.
317   Defective packet
318   Not from bound point.
319   Operation not permitted in current role.
320   Bad packet.
321   Message not authenticated.
322   No such oid.
323   Missing privacy parameter.
324   Bad engine id.
325   Bad time frame.
326   Bad user name.
327   Security level was not accepted.
328   Discovery failed.
329   Incorrect key length.
330   No authentication password supplied.
333   Returned OID was out of range. This is applicable only when WalkInsideRange is set to true.

The component may also return one of the following error codes, which are inherited from other components.

UDP Errors

104   UDP is already Active.
106   You cannot change the LocalPort while the component is Active.
107   You cannot change the LocalHost at this time. A connection is in progress.
109   The component must be Active for this operation.
112   Cannot change MaxPacketSize while the component is Active.
113   Cannot change ShareLocalPort option while the component is Active.
114   Cannot change RemoteHost when UseConnection is set and the component Active.
115   Cannot change RemotePort when UseConnection is set and the component is Active.
116   RemotePort can't be zero when UseConnection is set. Please specify a valid service port number.
117   Cannot change UseConnection while the component is Active.
118   Message can't be longer than MaxPacketSize.
119   Message too short.
434   Unable to convert string to selected CodePage

SSL Errors

270   Cannot load specified security library.
271   Cannot open certificate store.
272   Cannot find specified certificate.
273   Cannot acquire security credentials.
274   Cannot find certificate chain.
275   Cannot verify certificate chain.
276   Error during handshake.
280   Error verifying certificate.
281   Could not find client certificate.
282   Could not find server certificate.
283   Error encrypting data.
284   Error decrypting data.

TCP/IP Errors

10004   [10004] Interrupted system call.
10009   [10009] Bad file number.
10013   [10013] Access denied.
10014   [10014] Bad address.
10022   [10022] Invalid argument.
10024   [10024] Too many open files.
10035   [10035] Operation would block.
10036   [10036] Operation now in progress.
10037   [10037] Operation already in progress.
10038   [10038] Socket operation on non-socket.
10039   [10039] Destination address required.
10040   [10040] Message too long.
10041   [10041] Protocol wrong type for socket.
10042   [10042] Bad protocol option.
10043   [10043] Protocol not supported.
10044   [10044] Socket type not supported.
10045   [10045] Operation not supported on socket.
10046   [10046] Protocol family not supported.
10047   [10047] Address family not supported by protocol family.
10048   [10048] Address already in use.
10049   [10049] Can't assign requested address.
10050   [10050] Network is down.
10051   [10051] Network is unreachable.
10052   [10052] Net dropped connection or reset.
10053   [10053] Software caused connection abort.
10054   [10054] Connection reset by peer.
10055   [10055] No buffer space available.
10056   [10056] Socket is already connected.
10057   [10057] Socket is not connected.
10058   [10058] Can't send after socket shutdown.
10059   [10059] Too many references, can't splice.
10060   [10060] Connection timed out.
10061   [10061] Connection refused.
10062   [10062] Too many levels of symbolic links.
10063   [10063] File name too long.
10064   [10064] Host is down.
10065   [10065] No route to host.
10066   [10066] Directory not empty
10067   [10067] Too many processes.
10068   [10068] Too many users.
10069   [10069] Disc Quota Exceeded.
10070   [10070] Stale NFS file handle.
10071   [10071] Too many levels of remote in path.
10091   [10091] Network subsystem is unavailable.
10092   [10092] WINSOCK DLL Version out of range.
10093   [10093] Winsock not loaded yet.
11001   [11001] Host not found.
11002   [11002] Non-authoritative 'Host not found' (try again or check DNS setup).
11003   [11003] Non-recoverable errors: FORMERR, REFUSED, NOTIMP.
11004   [11004] Valid name, no data record (check DNS setup).

Copyright (c) 2022 /n software inc. - All rights reserved.
IPWorks SNMP 2022 .NET Edition - Version 22.0 [Build 8369]