SNMPMgr Class
Properties Methods Events Configuration Settings Errors
The SNMPMgr class is used to implement UDP-based SNMP Management Applications.
Syntax
class ipworkssnmp.SNMPMgr
Remarks
The SNMPMgr class implements a UDP-based standard SNMP Manager as specified in the SNMP RFCs. The class supports SNMP v1, v2c, and v3.
The class 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 class is activated/deactivated by setting the active property. This property enables or disables sending and receiving.
Messages are received through events such as on_response, on_trap, or on_inform_request. SNMP Traps are received through the on_trap event.
Messages are sent to other agents or managers by using class's methods such as send_get_request, send_get_next_request, send_get_bulk_request, send_set_request, and send_inform_request.
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, authentication_password, and encryption_password and calling the discover method to bind to a particular agent (remote_engine_id). 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 remote_engine_id, remote_engine_boots, and remote_engine_time are known in advance and provided to the class through the respective properties.
By default, the class 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 class returns control immediately after a send, and responses are received exclusively through the on_response event.
Property List
The following is the full list of the properties of the class with short descriptions. Click on the links for further details.
| accept_data | Enables or disables data reception. |
| active | Enables or disables sending and receiving of SNMP packets. |
| authentication_password | The password used for SNMPv3 authentication. |
| authentication_protocol | The authentication protocol used for SNMPv3 packets. |
| community | The community string used to authenticate SNMP packets. |
| encryption_algorithm | The encryption algorithm used for SNMPv3 packets. |
| encryption_password | The password used for SNMPv3 privacy. |
| error_description | Description of the status code for the last SNMP packet received by the class. |
| error_index | Index of the first variable (object) that caused an error from the last SNMP response. |
| error_status | Status code for the last SNMP packet received by the class. |
| local_engine_id | The Engine Id of the SNMP Manager. |
| local_host | The name of the local host or user-assigned IP interface through which connections are initiated or accepted. |
| local_port | The port in the local host where the SNMP Manager is bound to. |
| obj_count | The number of records in the Obj arrays. |
| obj_type | The current object's type. |
| obj_id | The current object's id which is encoded as a string of numbers separated by periods. |
| obj_type_string | A string representation of the current object's ObjectType . |
| obj_value | The current object's value. |
| remote_engine_boots | The remote engine boots (SNMPv3). |
| remote_engine_id | The Engine Id of the remote agent. |
| remote_engine_time | The remote engine time (SNMPv3). |
| remote_host | The address of the remote host. Domain names are resolved to IP addresses. |
| remote_port | The port where the remote SNMP agent is listening. |
| request_id | The request-id to mark outgoing packets with. |
| snmp_version | Version of SNMP used for outgoing requests. |
| store_walk_objects | Tells the class whether or not to store returned objects. |
| timeout | A timeout for the class. |
| user | The user name used for SNMPv3 authentication. |
| walk_limit | The limit of oid's returned in a walk. |
Method List
The following is the full list of the methods of the class with short descriptions. Click on the links for further details.
| config | Sets or retrieves a configuration setting. |
| discover | Performs SNMPv3 discovery. |
| do_events | Processes events from the internal message queue. |
| hash_passwords | Hashes all passwords in the cache. |
| interrupt | Interrupt the current method. |
| reset | Clears the object arrays. |
| send_get_bulk_request | Send a GetBulkRequest packet. |
| send_get_next_request | Send GetNextRequest packet. |
| send_get_request | Send GetRequest packet. |
| send_inform_request | Send an InformRequest packet. |
| send_set_request | Send Set Request packet. |
| value | Returns the value corresponding to an OID. |
| walk | Does an SNMP walk starting with the specified oid. |
Event List
The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.
| on_bad_packet | Fired for erroneous and/or malformed messages. |
| on_discovery_request | Fired when an SNMPv3 discovery packet is received. |
| on_discovery_response | Fired when an SNMPv3 discovery response is received. |
| on_error | Information about errors during data delivery. |
| on_hash_password | Fired before and after a password is hashed. |
| on_inform_request | Fired when an InformRequest packet is received. |
| on_packet_trace | Fired for every packet sent or received. |
| on_ready_to_send | Fired when the class is ready to send data. |
| on_report | Fired when a Report packet is received. |
| on_response | Fired when a GetResponse packet is received. |
| on_trap | Fired when a SNMP trap packet is received. |
Configuration Settings
The following is a list of configuration settings for the class with short descriptions. Click on the links for further details.
| AllowSingleStepDiscovery | Whether to allow discovery to be completed in a single step. |
| CheckMessageOrigin | Whether to match the origin IP address when receiving responses. |
| CompatibilityMode | Whether to operate the class in a specific compatibility mode. |
| ContextEngineId | Sets the context engine id of the SNMP entity. |
| ContextName | Sets the context name of the SNMP entity. |
| DecryptLogPackets | Whether to decrypt logged packets. |
| ForceLocalPort | Forces the class to bind to a specific port. |
| IgnorePortMismatch | Whether to check if the port matches when a response is received. |
| MsgMaxSize | The maximum supported message size. |
| SourceAddress | The source address of the received packet. |
| SourcePort | The source port of the received packet. |
| TimeoutInMilliseconds | The timeout is treated as milliseconds. |
| WalkInsideRange | Stops the SNMP walk if the OID value returned from an agent is outside the table. |
| WalkStartOID | Specifies the OID to be used when a Walk is performed. |
| 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 class 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 class to be active on the same local port. |
| SourceIPAddress | Used to set the source IP address used when sending a packet. |
| SourceMacAddress | Used to set the source MAC address used when sending a packet. |
| 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. |
| ProcessIdleEvents | Whether the class uses its internal event loop to process events when the main thread is idle. |
| SelectWaitMillis | The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process. |
| UseInternalSecurityAPI | Tells the class whether or not to use the system security libraries or an internal implementation. |