What is SNMP
Simple Network Management Protocol (SNMP) is an industry standard networking protocol used to monitor and manage network devices. MSP N-central uses SNMP to discover asset information and monitor the status of devices such as switches, routers, printers, servers.
Depending on the version of SNMP, the protocol itself includes the following actions:
|GetRequest||A request sent from the Manager to the Agent to retrieve variables.||1, 2, 3||What is the status of the network card?|
|SetRequest||A request sent from the Manager to the Agent to change the value of a variable or a list of variables.||1, 2, 3||Change the router's reported location to 'Downstairs Lab'.|
|GetNextRequest||An iterative request sent from the Manager to the Agent to discover available variables and their values after previously obtaining a value.||1, 2, 3||What is the status of the next network card?|
|GetBulkRequest||A request sent from the Manager to the Agent for multiple iterations of GetNextRequest.||2, 3||What is the status of the next three network cards?|
|Response||A message from the Agent to the Manager returning variable values and an acknowledgment. Note that in SNMP v1, this PDU was called GetResponse.||1, 2, 3||The status of the network card is Normal.|
|Trap||An unsolicited message sent from an Agent to a Manager.||1, 2, 3||A router is configured to send the traffic counters for an interface to a Manager device.|
|InformRequest||An acknowledged notification from a Manager to a Manager or from an Agent to a Manager. As delivery of Trap messages are not guaranteed, InformRequest overcomes this issue by sending back an acknowledgement upon receipt of the notification.||2, 3|
SNMP data is structured in a hierarchical (or nested) pattern that conforms to Abstract Syntax Notation One (ASN.1), a joint standard of the International Organization for Standardization (ISO), International Electrotechnical Commission (IEC), and International Telecommunication Union Telecommunication Standardization Sector ITU-T. For more information, refer to http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf.
SNMP data is arranged in a folder structure. The SNMP folder structure can be listed in words, for example, .Cisco.Switches.SerialNumber, or numerically, for example, .1.3.6.
SNMP queries are typically formatted as a numeric expression. This is referred to as an OID (Object Identifier).