SNMPAgent Component
Properties Methods Events Config Settings Errors
The SNMPAgent component is used to implement UDP-based SNMP Agent Applications.
Syntax
nsoftware.IPWorksSNMP.Snmpagent
Remarks
The SNMPAgent component implements a UDP-based standard SNMP Agent 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 agent as simple as setting a few key properties and handling a few events. SNMP data such as 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.
The component operates asynchronously. Requests are received through events such as GetRequest, GetBulkRequest, GetNextRequest, etc. and the corresponding responses are automatically sent when the events return. Traps are sent through the SendTrap method.
SNMPv3 USM security passwords are requested through the GetUserPassword event, and event parameters such as User and SecurityLevel provide information about the security attributes of received requests, and enable granular decision capability about what to provide and what not to provide. The SendSecureTrap method is used to send authenticated (secure) SNMPv3 traps.
The AddUser, RemoveUser, ShowCache, and ClearCache methods are used to manage an internal authentication cache. This internal cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.
SNMP OIDs, types, and values are provided in the Objects collection of SNMP objects for both sent and received packets.
Other packet information is provided through corresponding event parameters, such as Community, or RequestId.
Property List
The following is the full list of the properties of the component with short descriptions. Click on the links for further details.
AcceptData | Enables or disables data reception. |
Active | Indicates whether the component is active. |
LocalEngineId | The Engine Id of the SNMP Agent. |
LocalHost | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
LocalPort | The port in the local host where the component listens. |
Objects | The objects in the current request. |
RequestId | The request-id to mark outgoing packets with. |
SNMPVersion | Version of SNMP used for outgoing requests (traps). |
SysUpTime | Time passed since the agent was initialized (in hundredths of a second). |
Method List
The following is the full list of the methods of the component with short descriptions. Click on the links for further details.
Activate | Activates the component. |
AddUser | Adds a user to the internal authentication cache. |
ClearCache | Clears the internal authentication database. |
Config | Sets or retrieves a configuration setting. |
Deactivate | Deactivates the component. |
DoEvents | Processes events from the internal message queue. |
HashPasswords | Hashes all passwords in the cache. |
RemoveUser | Removes the user specified by User from the internal authentication cache. |
Reset | Clears the object arrays. |
SendResponse | Sends a response packet to a Get, Get-Next, Get-Bulk, or Set request. |
SendSecureResponse | Sends an authenticated and/or encrypted SNMPv3 response. |
SendSecureTrap | Sends an authenticated and/or encrypted SNMPv3 trap. |
SendTrap | Sends an SNMP Trap. |
ShowCache | Lists all entries in the internal user authentication cache. |
Value | Returns the value corresponding to an 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.
BadPacket | Fired for erroneous and/or malformed messages. |
CacheEntry | Shows in the internal cache. |
DiscoveryRequest | Fired when an SNMPv3 discovery packet is received. |
Error | Fired when information is available about errors during data delivery. |
GetBulkRequest | Fired when a GetBulkRequest packet is received. |
GetNextRequest | Fired when a GetNextRequest packet is received. |
GetRequest | Fired when a GetRequest packet is received. |
GetUserPassword | Retrieves a password associated with a user. |
GetUserSecurityLevel | Sets the security level for an incoming packet. |
HashPassword | Fired before and after a password is hashed. |
PacketTrace | Fired for every packet sent or received. |
ReadyToSend | Fired when the component is ready to send data. |
Report | Fired when a Report packet is received. |
SetRequest | Fired when a SetRequest 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.
AuthenticationKey | The key to use for authentication. |
CompatibilityMode | Whether to operate the component in a specific compatibility mode. |
ContextEngineId | Sets the context engine id of the SNMP entity. |
ContextName | Sets the context name of the SNMP entity. |
DataToSend | Sends a raw packet. |
DecryptLogPackets | Whether to decrypt logged packets. |
DerivedKeyCacheSize | The size of the internal cache used to store derived keys. |
DerivedKeyCacheStatus | The status of the internal cache used to store derived keys. |
EncryptionKey | The key to use for encryption. |
ForceLocalPort | Forces the component to bind to a specific port. |
IgnoreDiscoveryRequestType | Treats other request types as discovery requests. |
IncomingContextEngineId | The engine Id of the received packet. |
IncomingContextName | The context name of the received packet. |
MsgMaxSize | The maximum supported message size. |
RespondFromDestIP | Whether to respond from the IP address that the request was sent to. |
SourceAddress | The source address of the received packet. |
SourcePort | The source port of the received packet. |
SynchronizeEvents | Controls whether or not events are fired from the main thread when timeout is positive. |
TimeWindow | The time window used for SNMPv3 timeliness checking (authentication). |
TrapAgentAddress | The address of the object generating the trap. |
TrapCommunity | The value of the Community parameter for SNMP traps. |
TrapEnterprise | The type of the object generating the trap. |
TrapPort | The port where SNMP traps are sent. |
CaptureIPPacketInfo | Used to capture the packet information. |
DelayHostResolution | Whether the hostname is resolved when RemoteHost is set. |
DestinationAddress | Used to get the destination address from the packet information. |
DontFragment | Used to set the Don't Fragment flag of outgoing packets. |
LocalHost | The name of the local host through which connections are initiated or accepted. |
LocalPort | The port in the local host where the component binds. |
MaxPacketSize | The maximum length of the packets that can be received. |
QOSDSCPValue | Used to specify an arbitrary QOS/DSCP setting (optional). |
QOSTrafficType | Used to specify QOS/DSCP settings (optional). |
ShareLocalPort | If set to True, allows more than one instance of the component to be active on the same local port. |
UseConnection | Determines whether to use a connected socket. |
UseIPv6 | Whether or not to use IPv6. |
AbsoluteTimeout | Determines whether timeouts are inactivity timeouts or absolute timeouts. |
FirewallData | Used to send extra data to the firewall. |
InBufferSize | The size in bytes of the incoming queue of the socket. |
OutBufferSize | The size in bytes of the outgoing queue of the socket. |
BuildInfo | Information about the product's build. |
GUIAvailable | Whether or not a message loop is available for processing events. |
LicenseInfo | Information about the current license. |
MaskSensitive | Whether sensitive data is masked in log messages. |
UseInternalSecurityAPI | Whether or not to use the system security libraries or an internal implementation. |
AcceptData Property (SNMPAgent Component)
Enables or disables data reception.
Syntax
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 (SNMPAgent Component)
Indicates whether the component is active.
Syntax
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.
LocalEngineId Property (SNMPAgent Component)
The Engine Id of the SNMP Agent.
Syntax
Default Value
""
Remarks
This property is only used for SNMPv3 packets (when SNMPVersion is 3).
LocalHost Property (SNMPAgent Component)
The name of the local host or user-assigned IP interface through which connections are initiated or accepted.
Syntax
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 (SNMPAgent Component)
The port in the local host where the component listens.
Syntax
Default Value
161
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 (default 161).
You may also set LocalPort to 0. This allows the TCP/IP stack to choose a port at random. The value chosen is provided via the LocalPort property after the component is activated through the Active property.
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 (SNMPAgent 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.
Please refer to the SNMPObject type for a complete list of fields.RequestId Property (SNMPAgent Component)
The request-id to mark outgoing packets with.
Syntax
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 (SNMPAgent Component)
Version of SNMP used for outgoing requests (traps).
Syntax
public SnmpagentSNMPVersions SNMPVersion { get; set; }
enum SnmpagentSNMPVersions { snmpverV1, snmpverV2c, snmpverV3 }
Public Property SNMPVersion As SnmpagentSNMPVersions
Enum SnmpagentSNMPVersions 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. |
SysUpTime Property (SNMPAgent Component)
Time passed since the agent was initialized (in hundredths of a second).
Syntax
Default Value
0
Remarks
This property is used when sending SNMP traps, and it normally provides the time since the system was restarted in 1/100s of a second.
If another value is desired, you may set this property to a custom value. From that point on, SysUpTime will return the value set plus time elapsed.
This property is not available at design time.
Activate Method (SNMPAgent 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.
AddUser Method (SNMPAgent Component)
Adds a user to the internal authentication cache.
Syntax
public void AddUser(string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); Async Version public async Task AddUser(string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); public async Task AddUser(string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword, CancellationToken cancellationToken);
Public Sub AddUser(ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) Async Version Public Sub AddUser(ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) As Task Public Sub AddUser(ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String, cancellationToken As CancellationToken) As Task
Remarks
The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.
The ShowCache method is used to show the contents of the internal authentication cache.
The ClearCache method can be used to completely clear the cache.
Valid Authentication Protocols are:
HMAC-MD5-96 (1) | Message-Digest algorithm 5. |
HMAC-SHA-96 (2) | Secure Hash Algorithm. |
HMAC-192-SHA-256 (3) | Secure Hash Algorithm. |
HMAC-384-SHA-512 (4) | Secure Hash Algorithm. |
Valid Encryption Algorithms 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. |
NOTE: Specifying an authentication protocol of 0 is a special case where the component will attempt to verify users with all valid authentication protocols.
ClearCache Method (SNMPAgent Component)
Clears the internal authentication database.
Syntax
public void ClearCache(); Async Version public async Task ClearCache(); public async Task ClearCache(CancellationToken cancellationToken);
Public Sub ClearCache() Async Version Public Sub ClearCache() As Task Public Sub ClearCache(cancellationToken As CancellationToken) As Task
Remarks
All user records are removed from the internal authentication cache as a result of this call.
Config Method (SNMPAgent Component)
Sets or retrieves a configuration setting.
Syntax
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 (SNMPAgent 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.
DoEvents Method (SNMPAgent 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 (SNMPAgent 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.
RemoveUser Method (SNMPAgent Component)
Removes the user specified by User from the internal authentication cache.
Syntax
public void RemoveUser(string user); Async Version public async Task RemoveUser(string user); public async Task RemoveUser(string user, CancellationToken cancellationToken);
Public Sub RemoveUser(ByVal User As String) Async Version Public Sub RemoveUser(ByVal User As String) As Task Public Sub RemoveUser(ByVal User As String, cancellationToken As CancellationToken) As Task
Remarks
The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.
The ShowCache method is used to show the contents of the internal authentication cache.
The ClearCache method can be used to completely clear the cache.
Reset Method (SNMPAgent 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).
SendResponse Method (SNMPAgent Component)
Sends a response packet to a Get, Get-Next, Get-Bulk, or Set request.
Syntax
public void SendResponse(string remoteHost, int remotePort, int requestId, string community, int errorStatus, int errorIndex); Async Version public async Task SendResponse(string remoteHost, int remotePort, int requestId, string community, int errorStatus, int errorIndex); public async Task SendResponse(string remoteHost, int remotePort, int requestId, string community, int errorStatus, int errorIndex, CancellationToken cancellationToken);
Public Sub SendResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal Community As String, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer) Async Version Public Sub SendResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal Community As String, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer) As Task Public Sub SendResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal Community As String, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer, cancellationToken As CancellationToken) As Task
Remarks
Use this method to send asynchronous response packets. A valid RequestId must be specified. SendResponse sends an unauthenticated response packet. Depending upon the value of the SNMPVersion property, the packet is constructed as an SNMPv1, SNMPv2c, or SNMPv3 (unauthenticated) response PDU. To send authenticated or encrypted SNMPv3 responses, use SendSecureResponse
The RemoteHost and RemotePort parameters are used to determine where the response is to be sent. The object identifiers, types, and values for the request are taken from the Objects collection. The RequestId, Community, ErrorStatus, and ErrorIndex parameters are used to specify other properties of the response.
SendSecureResponse Method (SNMPAgent Component)
Sends an authenticated and/or encrypted SNMPv3 response.
Syntax
public void SendSecureResponse(string remoteHost, int remotePort, int requestId, int messageId, int errorStatus, int errorIndex, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); Async Version public async Task SendSecureResponse(string remoteHost, int remotePort, int requestId, int messageId, int errorStatus, int errorIndex, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); public async Task SendSecureResponse(string remoteHost, int remotePort, int requestId, int messageId, int errorStatus, int errorIndex, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword, CancellationToken cancellationToken);
Public Sub SendSecureResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal MessageId As Integer, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) Async Version Public Sub SendSecureResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal MessageId As Integer, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) As Task Public Sub SendSecureResponse(ByVal RemoteHost As String, ByVal RemotePort As Integer, ByVal RequestId As Integer, ByVal MessageId As Integer, ByVal ErrorStatus As Integer, ByVal ErrorIndex As Integer, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String, cancellationToken As CancellationToken) As Task
Remarks
Similar to the SendResponse method except that User, Authentication Protocol, and AuthenticationPassword are used to authenticate the response. EncryptionAlgorithm and EncryptionPassword (if not empty) are used to encrypt the response.
The MessageId argument must match the MessageId parameter obtained from the GetRequest, GetNextRequest, SetRequest, or GetBulkRequest event.
The user and password arguments used to send the response will be added to the internal user cache. If the user is already in the cache, its passwords will be updated with those supplied.
Valid Authentication Protocols are:
HMAC-MD5-96 (1) | Message-Digest algorithm 5. |
HMAC-SHA-96 (2) | Secure Hash Algorithm. |
HMAC-192-SHA-256 (3) | Secure Hash Algorithm. |
HMAC-384-SHA-512 (4) | Secure Hash Algorithm. |
Valid Encryption Algorithms 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. |
SendSecureTrap Method (SNMPAgent Component)
Sends an authenticated and/or encrypted SNMPv3 trap.
Syntax
public void SendSecureTrap(string remoteHost, string trapOID, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); Async Version public async Task SendSecureTrap(string remoteHost, string trapOID, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword); public async Task SendSecureTrap(string remoteHost, string trapOID, string user, int authenticationProtocol, string authenticationPassword, int encryptionAlgorithm, string encryptionPassword, CancellationToken cancellationToken);
Public Sub SendSecureTrap(ByVal RemoteHost As String, ByVal TrapOID As String, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) Async Version Public Sub SendSecureTrap(ByVal RemoteHost As String, ByVal TrapOID As String, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String) As Task Public Sub SendSecureTrap(ByVal RemoteHost As String, ByVal TrapOID As String, ByVal User As String, ByVal AuthenticationProtocol As Integer, ByVal AuthenticationPassword As String, ByVal EncryptionAlgorithm As Integer, ByVal EncryptionPassword As String, cancellationToken As CancellationToken) As Task
Remarks
Similar to the SendTrap method except that User, AuthenticationPassword, and Authentication Protocol are used to authenticate the trap. EncryptionPassword (if not empty) and EncryptionAlgorithm are used to encrypt the message.
The user and password arguments used to send the trap will be added to the internal user cache. If the user is already in the cache, its passwords will be updated with those supplied.
Valid Authentication Protocols are:
HMAC-MD5-96 (1) | Message-Digest algorithm 5. |
HMAC-SHA-96 (2) | Secure Hash Algorithm. |
HMAC-192-SHA-256 (3) | Secure Hash Algorithm. |
HMAC-384-SHA-512 (4) | Secure Hash Algorithm. |
Valid Encryption Algorithms 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. |
SendTrap Method (SNMPAgent Component)
Sends an SNMP Trap.
Syntax
Remarks
Depending upon the value of the SNMPVersion property, the packet is constructed as an SNMPv1 or SNMPv2 Trap PDU. The following configuration settings provide more control about how traps are generated: TrapPort, TrapAgentAddress, TrapCommunity, TrapEnterprise. The SysUpTime property provides the trap timestamp.
SendTrap sends an unauthenticated trap. The SendSecureTrap method is used to send authenticated SNMPv3 traps.
If any values are provided in the Objects collection, they are sent unchanged. In the case of an SNMPv2 or SNMPv3 Trap, if Objects has a count that is equal to 0, the following values are set: sysUpTime.0 equal to SysUpTime and snmpTrapOID.0 equal to TrapOID.
For SNMPv2 and SNMPv3 Traps, TrapOID must contain the full OID of the Trap. For SNMPv1, TrapOID must be a string of the form "generic.specific" where generic and specific are numeric values providing the Trap Generic Type and Specific Type.
For SNMPv1, TrapOID must be of the form "GenericTrap.SpecificTrap". These values are sent in the PDU header. TrapAgentAddress and TrapEnterprise are taken from the corresponding configuration settings.
Additionally, the following symbolic values are recognized and translated as follows:
Trap Name | OID (SNMPv2 and above) | SNMPv1 GenericType |
coldStart | 1.3.6.1.6.3.1.1.5.1 | 0 |
warmStart | 1.3.6.1.6.3.1.1.5.2 | 1 |
linkDown | 1.3.6.1.6.3.1.1.5.3 | 2 |
linkUp | 1.3.6.1.6.3.1.1.5.4 | 3 |
authenticationFailure | 1.3.6.1.6.3.1.1.5.5 | 4 |
egpNeighborLoss | 1.3.6.1.6.3.1.1.5.6 | 5 |
enterpriseSpecific | 1.3.6.1.6.3.1.1.5.7 | 6 |
ShowCache Method (SNMPAgent Component)
Lists all entries in the internal user authentication cache.
Syntax
public void ShowCache(); Async Version public async Task ShowCache(); public async Task ShowCache(CancellationToken cancellationToken);
Public Sub ShowCache() Async Version Public Sub ShowCache() As Task Public Sub ShowCache(cancellationToken As CancellationToken) As Task
Remarks
A CacheEntry event is fired for every record in the internal user authentication cache.
The internal authentication cache can be used as an alternative to the GetUserPassword event, automatically checking the cache against the security parameters provided in the request signature.
The ShowCache method is used to show the contents of the internal authentication cache.
The ClearCache method can be used to completely clear the cache.
Value Method (SNMPAgent Component)
Returns the value corresponding to an OID.
Syntax
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.
BadPacket Event (SNMPAgent Component)
Fired for erroneous and/or malformed messages.
Syntax
public event OnBadPacketHandler OnBadPacket; public delegate void OnBadPacketHandler(object sender, SnmpagentBadPacketEventArgs e); public class SnmpagentBadPacketEventArgs : 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 SnmpagentBadPacketEventArgs) Public Class SnmpagentBadPacketEventArgs 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.
Please refer to the GetUserPassword event for more information concerning SNMPv3 authentication.
CacheEntry Event (SNMPAgent Component)
Shows in the internal cache.
Syntax
public event OnCacheEntryHandler OnCacheEntry; public delegate void OnCacheEntryHandler(object sender, SnmpagentCacheEntryEventArgs e); public class SnmpagentCacheEntryEventArgs : EventArgs { public string User { get; } public string AuthenticationProtocol { get; } public string AuthenticationPassword { get; } public string EncryptionAlgorithm { get; } public string EncryptionPassword { get; } }
Public Event OnCacheEntry As OnCacheEntryHandler Public Delegate Sub OnCacheEntryHandler(sender As Object, e As SnmpagentCacheEntryEventArgs) Public Class SnmpagentCacheEntryEventArgs Inherits EventArgs Public ReadOnly Property User As String Public ReadOnly Property AuthenticationProtocol As String Public ReadOnly Property AuthenticationPassword As String Public ReadOnly Property EncryptionAlgorithm As String Public ReadOnly Property EncryptionPassword As String End Class
Remarks
CacheEntry events are triggered by a call to ShowCache. One event is fired for each user.
DiscoveryRequest Event (SNMPAgent Component)
Fired when an SNMPv3 discovery packet is received.
Syntax
public event OnDiscoveryRequestHandler OnDiscoveryRequest; public delegate void OnDiscoveryRequestHandler(object sender, SnmpagentDiscoveryRequestEventArgs e); public class SnmpagentDiscoveryRequestEventArgs : 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 SnmpagentDiscoveryRequestEventArgs) Public Class SnmpagentDiscoveryRequestEventArgs 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).
Error Event (SNMPAgent Component)
Fired when information is available about errors during data delivery.
Syntax
public event OnErrorHandler OnError; public delegate void OnErrorHandler(object sender, SnmpagentErrorEventArgs e); public class SnmpagentErrorEventArgs : EventArgs { public int ErrorCode { get; } public string Description { get; } }
Public Event OnError As OnErrorHandler Public Delegate Sub OnErrorHandler(sender As Object, e As SnmpagentErrorEventArgs) Public Class SnmpagentErrorEventArgs 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.
GetBulkRequest Event (SNMPAgent Component)
Fired when a GetBulkRequest packet is received.
Syntax
public event OnGetBulkRequestHandler OnGetBulkRequest; public delegate void OnGetBulkRequestHandler(object sender, SnmpagentGetBulkRequestEventArgs e); public class SnmpagentGetBulkRequestEventArgs : EventArgs { public int RequestId { get; } public int MessageId { 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 NonRepeaters { get; } public int MaxRepetitions { get; } public int ErrorIndex { get; set; } public int ErrorStatus { get; set; } public string ErrorDescription { get; } public bool Respond { get; set; } }
Public Event OnGetBulkRequest As OnGetBulkRequestHandler Public Delegate Sub OnGetBulkRequestHandler(sender As Object, e As SnmpagentGetBulkRequestEventArgs) Public Class SnmpagentGetBulkRequestEventArgs Inherits EventArgs Public ReadOnly Property RequestId As Integer Public ReadOnly Property MessageId 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 NonRepeaters As Integer Public ReadOnly Property MaxRepetitions 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
This is only available for SNMP versions 2 and 3.
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. |
Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).
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.
GetNextRequest Event (SNMPAgent Component)
Fired when a GetNextRequest packet is received.
Syntax
public event OnGetNextRequestHandler OnGetNextRequest; public delegate void OnGetNextRequestHandler(object sender, SnmpagentGetNextRequestEventArgs e); public class SnmpagentGetNextRequestEventArgs : EventArgs { public int RequestId { get; } public int MessageId { 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 OnGetNextRequest As OnGetNextRequestHandler Public Delegate Sub OnGetNextRequestHandler(sender As Object, e As SnmpagentGetNextRequestEventArgs) Public Class SnmpagentGetNextRequestEventArgs Inherits EventArgs Public ReadOnly Property RequestId As Integer Public ReadOnly Property MessageId 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 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. |
Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).
GetRequest Event (SNMPAgent Component)
Fired when a GetRequest packet is received.
Syntax
public event OnGetRequestHandler OnGetRequest; public delegate void OnGetRequestHandler(object sender, SnmpagentGetRequestEventArgs e); public class SnmpagentGetRequestEventArgs : EventArgs { public int RequestId { get; } public int MessageId { 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 OnGetRequest As OnGetRequestHandler Public Delegate Sub OnGetRequestHandler(sender As Object, e As SnmpagentGetRequestEventArgs) Public Class SnmpagentGetRequestEventArgs Inherits EventArgs Public ReadOnly Property RequestId As Integer Public ReadOnly Property MessageId 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 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. |
Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).
GetUserPassword Event (SNMPAgent Component)
Retrieves a password associated with a user.
Syntax
public event OnGetUserPasswordHandler OnGetUserPassword; public delegate void OnGetUserPasswordHandler(object sender, SnmpagentGetUserPasswordEventArgs e); public class SnmpagentGetUserPasswordEventArgs : EventArgs { public int PasswordType { get; } public string User { get; } public string Password { get; set; } public int Algorithm { get; set; } }
Public Event OnGetUserPassword As OnGetUserPasswordHandler Public Delegate Sub OnGetUserPasswordHandler(sender As Object, e As SnmpagentGetUserPasswordEventArgs) Public Class SnmpagentGetUserPasswordEventArgs Inherits EventArgs Public ReadOnly Property PasswordType As Integer Public ReadOnly Property User As String Public Property Password As String Public Property Algorithm As Integer End Class
Remarks
The GetUserPassword event is fired after initial inspection of SNMPv3 requests.
The type of password required is provided in the PasswordType parameter: 1 for authentication, and 2 for encryption (privacy).
The password corresponding to User (if any) must be provided in the Password parameter. If the password is valid, processing will continue to other events such as GetRequest, SetRequest, etc.
If the PasswordType parameter is 1 (authentication is used), the Algorithm parameter can be set. Possible values are:
Value | Authentication Algorithm |
0 (default) | Any |
1 | MD5 |
2 | SHA1 |
3 | SHA256 |
4 | SHA512 |
Value | Encryption Algorithm |
1 (default) | DES |
2 | AES |
3 | 3DES |
4 | AES192 |
5 | AES256 |
If the password does not match the signature in the request, a BadPacket event will be fired, at which point you can decide whether to report the error to the client (see the description of the BadPacket event for more information).
If the User is invalid or unknown, set the password to empty string (default) to ignore the request. This will result in a BadPacket event being fired, at which point you can decide whether to report the error to the client or not.
GetUserSecurityLevel Event (SNMPAgent Component)
Sets the security level for an incoming packet.
Syntax
public event OnGetUserSecurityLevelHandler OnGetUserSecurityLevel; public delegate void OnGetUserSecurityLevelHandler(object sender, SnmpagentGetUserSecurityLevelEventArgs e); public class SnmpagentGetUserSecurityLevelEventArgs : EventArgs { public string User { get; } public string EngineId { get; }
public byte[] EngineIdB { get; } public int SecurityLevel { get; set; } }
Public Event OnGetUserSecurityLevel As OnGetUserSecurityLevelHandler Public Delegate Sub OnGetUserSecurityLevelHandler(sender As Object, e As SnmpagentGetUserSecurityLevelEventArgs) Public Class SnmpagentGetUserSecurityLevelEventArgs Inherits EventArgs Public ReadOnly Property User As String Public ReadOnly Property EngineId As String
Public ReadOnly Property EngineIdB As Byte() Public Property SecurityLevel As Integer End Class
Remarks
The GetUserSecurityLevel event is fired after the first inspection of each SNMPv3 request. The SecurityLevel parameter determines the level of security for the message.
On entry, the SecurityLevel parameter contains the default security level for User if the user is located in the internal cache, or if the User is not found in the cache, the SecurityLevel will be -1.
The value of SecurityLevel upon exiting the event, determines how the message will be processed:
-1 | The message will be ignored and a BadPacket event will be fired. |
0 | No security. The message will be processed without any authentication and/or encryption. |
1 | Authentication only. The message will be checked for a valid signature and the GetUserPassword event will be fired to verify the authentication password. |
2 | Authentication and Privacy. The message will be checked for a valid signature and the GetUserPassword event will be fired twice: first to verify the authentication password, and then to verify the privacy password. |
HashPassword Event (SNMPAgent Component)
Fired before and after a password is hashed.
Syntax
public event OnHashPasswordHandler OnHashPassword; public delegate void OnHashPasswordHandler(object sender, SnmpagentHashPasswordEventArgs e); public class SnmpagentHashPasswordEventArgs : 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 SnmpagentHashPasswordEventArgs) Public Class SnmpagentHashPasswordEventArgs 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
PacketTrace Event (SNMPAgent Component)
Fired for every packet sent or received.
Syntax
public event OnPacketTraceHandler OnPacketTrace; public delegate void OnPacketTraceHandler(object sender, SnmpagentPacketTraceEventArgs e); public class SnmpagentPacketTraceEventArgs : 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 SnmpagentPacketTraceEventArgs) Public Class SnmpagentPacketTraceEventArgs 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 (SNMPAgent Component)
Fired when the component is ready to send data.
Syntax
public event OnReadyToSendHandler OnReadyToSend; public delegate void OnReadyToSendHandler(object sender, SnmpagentReadyToSendEventArgs e); public class SnmpagentReadyToSendEventArgs : EventArgs { }
Public Event OnReadyToSend As OnReadyToSendHandler Public Delegate Sub OnReadyToSendHandler(sender As Object, e As SnmpagentReadyToSendEventArgs) Public Class SnmpagentReadyToSendEventArgs 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 (SNMPAgent Component)
Fired when a Report packet is received.
Syntax
public event OnReportHandler OnReport; public delegate void OnReportHandler(object sender, SnmpagentReportEventArgs e); public class SnmpagentReportEventArgs : 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 SnmpagentReportEventArgs) Public Class SnmpagentReportEventArgs 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.
SetRequest Event (SNMPAgent Component)
Fired when a SetRequest packet is received.
Syntax
public event OnSetRequestHandler OnSetRequest; public delegate void OnSetRequestHandler(object sender, SnmpagentSetRequestEventArgs e); public class SnmpagentSetRequestEventArgs : EventArgs { public int RequestId { get; } public int MessageId { 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 OnSetRequest As OnSetRequestHandler Public Delegate Sub OnSetRequestHandler(sender As Object, e As SnmpagentSetRequestEventArgs) Public Class SnmpagentSetRequestEventArgs Inherits EventArgs Public ReadOnly Property RequestId As Integer Public ReadOnly Property MessageId 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 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. |
Variable indexes start with 0. ErrorIndex has no meaning when ErrorStatus is 0 (no error).
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
Default Value: 5
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
Default Value: ""
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 (read-only)
Default Value: ""
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
Default Value: ""
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 []
Default Value: ""
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(string oid);
Public SNMPObject(ByVal Oid As String)
public SNMPObject(string oid, byte[] value);
Public SNMPObject(ByVal Oid As String, ByVal Value As Byte())
public SNMPObject(string oid, byte[] value, SNMPObjectTypes SNMPObjectType);
Public SNMPObject(ByVal Oid As String, ByVal Value As Byte(), ByVal SNMPObjectType As SNMPObjectTypes)
Config Settings (SNMPAgent 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.SNMPAgent Config Settings
0 (default) | Component operates normally for greatest compatibility. |
1 | Component uses SNMP4j-compatible encryption (AES192 and AES256). |
2 | Component automatically detects whether to use SNMP4j-compatible encryption (AES192 and AES256). Note: This option is only applicable when receiving packets. If you are using SNMPMgr or sending secure traps, you will need to select either 0 or 1. |
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.
A valid port number (a value between 1 and 65535) is required. The default value is 162.
UDP Config Settings
The default value for this setting is False.
Note: This setting is only available in Windows.
The default value is false for the default library and true for the Async library. The default value is false.
Note: This setting is only available in Windows.
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).
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.
Note: This setting uses the qWAVE API is only available on Windows 7, Windows Server 2008 R2, and later.
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.
The default value for this setting is False.
The default value for this setting is False.
Socket Config Settings
Note: This option is not valid for UDP ports.
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.
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
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.
- 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.
This setting only works on these components: AS3Receiver, AS3Sender, Atom, Client(3DS), FTP, FTPServer, IMAP, OFTPClient, SSHClient, SCP, Server(3DS), Sexec, SFTP, SFTPServer, SSHServer, TCPClient, TCPServer.
Setting this configuration setting to true tells the component to use the internal implementation instead of using the system security libraries.
On Windows, this setting is set to false by default. On Linux/macOS, this setting is set to true by default.
If using the .NET Standard Library, this setting will be true on all platforms. The .NET Standard library does not support using the system security libraries.
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 dynamic link library (DLL) is no longer required as a reference, as all unmanaged code is stored in that file.
Trappable Errors (SNMPAgent Component)
SNMPAgent Errors
201 Timeout. | |
301 Bad Object Index. | |
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. |
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). |