SNMP is a protocol for monitoring network devices like routers and switches. It consists of agents running on devices that collect data, and a network management system that issues requests to the agents. Agents respond to requests from the management system to retrieve or set values of objects identified by OIDs. The SNMP protocol uses various PDUs like GetRequest, SetRequest, and Response to communicate between agents and the management system.

1. Chapter No. 9
SNMP-Simple Network
Management Protocol

2. Syllabus
• An IP Management Protocol
• Network Management protocols
• SNMP the Simple Network Management
• Protocol, Agents & Managers, SNMP
• organization, Object Identifiers,
• Problem with SNMP

3. SNMP
• Simple Network Management Protocol (SNMP) is
an "Internet-standard protocol for managing devices
on IP networks." Devices that typically support
SNMP include routers, switches, servers,
workstations, printers, modem racks, and more.”

4. An SNMP-managed network consists of three key
components:
• Managed device
• Agent — software which runs on managed devices
• Network management system (NMS) — software
which runs on the manager

5. • SNMP Protocol :-
SNMP operates in the Application Layer of the Internet Protocol
Suite (Layer 7 of the OSI model). The SNMP agent receives
requests on UDP port 161.
The manager may send requests from any available source port to
port 161 in the agent.
The agent response will be sent back to the source port on the
manager.
The manager receives notifications (Traps and InformRequests)
on port 162.

6. The seven SNMP protocol data units (PDUs) are as follows:
• GetRequest
• SetRequest
• GetNextRequest
• GetBulkRequest

7. • Response
Returns variable bindings and acknowledgement from
agent to manager for GetRequest, SetRequest,
GetNextRequest, GetBulkRequest and InformRequest.

8. • Object Identifier:-
In computing, an object identifier or OID is an identifier used to
name an object (compare URN).