PDUs
The SNMP protocol is based on the exchange of protocol data units, or PDUs, between the SNMP manager and the SNMP agent.
SNMP has seven types of PDUs:
- GetRequest-PDU
- Sent from the manager to request information from the agent.
- GetNextRequest-PDU
- Requests the next variable in the MIB tree.
- GetBulkRequest-PDU
- Requests the next variable in the MIB tree and can also be used to specify multiple successors.
- GetResponse-PDU
- Sent from the agent to return information to the manager.
- SetRequest-PDU
- Sent from the manager to alter information at the agent.
- Trap-PDU
- Sent from the agent to report network events to the manager. A trap is an unconfirmed notification.
- Inform-PDU
- Sent from an agent to a manager or from a manager to another manager to report a network event. Attempts to confirm delivery are made for Inform-PDUs, not Trap-PDUs.