SNMPMgr Component

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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.

Method List

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

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.

Config Settings

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

AcceptData Property (SNMPMgr Component)

Enables or disables data reception.

Syntax

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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:

This property is not available at design time.

EncryptionPassword Property (SNMPMgr Component)

The password used for SNMPv3 privacy.

Syntax

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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:

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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:

StoreWalkObjects Property (SNMPMgr Component)

Tells the component whether or not to store returned objects.

Syntax

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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:

SendGetNextRequest Method (SNMPMgr Component)

Send GetNextRequest packet.

Syntax

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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)

Fired when information is available about errors during data delivery.

Syntax

• C#
• VB.NET

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.

The ErrorCode parameter contains an error code, and the Description parameter 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

• C#
• VB.NET

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

• C#
• VB.NET

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:

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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

• C#
• VB.NET

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:

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

• C#
• VB.NET

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

Constructors

• C#
• VB.NET

public SNMPObject();

Public SNMPObject()

• C#
• VB.NET

public SNMPObject(string oid);

Public SNMPObject(ByVal Oid As String)

• C#
• VB.NET

public SNMPObject(string oid, byte[] value);

Public SNMPObject(ByVal Oid As String, ByVal Value As Byte())

• C#
• VB.NET

public SNMPObject(string oid, byte[] value, SNMPObjectTypes SNMPObjectType);

Public SNMPObject(ByVal Oid As String, ByVal Value As Byte(), ByVal SNMPObjectType As SNMPObjectTypes)

Config Settings (SNMPMgr Component)

SNMPManager Config Settings

UDP Config Settings

Socket Config Settings

Base Config Settings

Trappable Errors (SNMPMgr Component)

SNMPMgr Errors

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

UDP Errors

SSL Errors

TCP/IP Errors