What is SNMP?

SNMP is short for "Simple Network Management Protocol". It is a set of several protocol definitions for managing networks. There are several versions of this protocol, the first versions of SNMP were developed in the early 80s.

SNMP works by sending messages (requests) to some device of a network which sends back the requested information. The requesting machine specifies the desired value with an OID (Object IDentifier) which, for example, can look like this:

1.3.6.1.2.1.25.3.3.1.2.2

Relax, for most uses of PRTG Traffic Grapher you don't need to handle any OIDs, PRTG Traffic Grapher has the most common ones stored inside the product. You will have to enter a specific OID into the program for special tasks only.

These OIDs are usually taken out of so called MIBs (Management Information Bases) which are published by the hardware manufacturers, because the OIDs often vary from one device to another.

E.g. there are OIDs for CPU usage, available disk space, transferred bytes over a network port, printed pages of a printer, and some devices even offer the room temperature as a value for environmental monitoring.