Brief Introduction to SNMP protocol

SNMP: (SNMP: Simple Network Management Protocol)

SNMP is a standard protocol used to manage network nodes (servers, workstations, routers, switches, and hubs) in an IP network. It is an application layer protocol. SNMP enables network administrators to manage network performance, discover and solve network problems, and plan network growth. The Network Management System receives random messages (and event reports) through SNMP to learn about network problems.

The SNMP management network consists of three main components: managed devices, proxies, and network management systems. A management device is a network node that contains an anmp proxy and is in the management network. Managed devices are used to collect and store management information. Through SNMP, NMS can obtain this information. Managed devices, sometimes called network units, may refer to routers, access servers, switches and bridges, hubs, hosts, or printers. The SNMP agent is a network management software module on the managed device. The SNMP agent has local management information and converts them to an SNMP-compatible format. NMS running applicationsProgramTo monitor managed devices. In addition, NMs provides a large number of processing programs and necessary storage resources for network management. Any managed network requires at least one or more NMS.

Currently, three types of SNMP are available: SNMPv1, SNMPv2, and SNMPv3. There is no big gap between version 1st and version 2nd, but SNMPv2 is an enhanced version that includes other protocol operations. Compared with the first two methods, SNMPv3 includes more security and remote configuration. To solve the incompatibility problem between different SNMP versions, rfc3584 defines three coexistence policies.

SNMP also includes a set of extension protocols defined by rmon, rmon2, MTB, mtb2, OCDs, and OCDs.

 

Protocol Structure

 

SNMP is an application protocol encapsulated in UDP. Common SNMP information formats of different versions are as follows:

 

Version

Community

PDU

 

Version: SNMP version. The manager and agent must use the same version of SNMP. You need to delete information with different version numbers without further processing them. community: group name, used to authenticate the manager before accessing the proxy. PDU (Protocol Data Unit): The PDU types and formats in SNMPv1, V2, and V3 are described in the corresponding files.