The Simple Network Management Protocol (SNMP) is
|“||[a] standard TCP/IP protocol for network management. Network administrators use SNMP to monitor and map network availability, performance, and error rates.||”|
To work with SNMP, network devices utilize a distributed data store called the Management Information Base (MIB). All SNMP-compliant devices contain a MIB which supplies the pertinent attributes of a device. Some attributes are fixed or "hard-coded" in the MIB, while others are dynamic values calculated by agent software running on the device.
SNMP is used to manage all types of network devices on the Internet. SNMP uses two ports: 161 and 162. Although SNMP is an extremely useful service for maintaining a network, it is very weak in security.
"The first versions of SNMP were developed in the early 80s. SNMP works by sending messages, called protocol data units (PDUs), to different parts of a network. SNMP-compliant devices, called agents, store data about themselves in Management Information Bases (MIBs) and return this data to the SNMP requesters."