The SNMPAgent component is used to implement UDP-based SNMP Agent Applications.
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 setting the Active property. This property enables or disables sending and receiving.
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.
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||Enables or disables sending and receiving of SNMP packets.|
|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).|
The following is the full list of the methods of the component with short descriptions. Click on the links for further details.
|AddUser||Adds a user to the internal authentication cache.|
|ClearCache||Clears the internal authentication database.|
|Config||Sets or retrieves a configuration setting.|
|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.|
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||Information 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.|
The following is a list of configuration 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.|
|EncryptionKey||The key to use for encryption.|
|ForceLocalPort||Forces the component to bind to a specific port.|
|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.|
|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.|
|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.|
|CodePage||The system code page used for Unicode to Multibyte translations.|
|LicenseInfo||Information about the current license.|
|UseInternalSecurityAPI||Tells the component whether or not to use the system security libraries or an internal implementation.|