Network management requires technology capable of monitoring and controlling devices on an internet. Network management technology is used to monitor such parameters as network performance, resource consumption, and abnormal network behavior. It can control the state of network devices, abnormal events, and access to the internet. It can also report unusual network conditions and events.
Open internetworking technologies such as TCP/IP allow an almost limitless combination of devices and media from different vendors to participate in an internet. Any functional management technology for an internet, therefore, must be vendor-independent. The Simple Network Management Protocol (SNMP) is one management technology used to monitor and control devices on TCP/IP-based networks. It allows the retrieval and alteration of network information maintained in the Management Information Base (MIB) by these devices.
The MIB is a tree-structured collection of objects which are accessible via SNMP. The branches of the tree comprise logically related groups of managed objects. All implementations of SNMP can expect to find internet standard object groups in the MIB; objects that are specific to a particular vendor's SNMP implementation can be defined in the enterprises branch of the MIB. These abstract objects are templates that describe an object identifier (name) and type for the actual object instances which are manipulated by SNMP. To access an object instance on a managed device, both the object's identifier and the instance identifier must be known.
SNMP systems are typically composed of network management stations and SNMP agents in network devices such as hosts, gateways, routers, and terminal servers. Network management stations are used to issue requests for retrieving or changing information in the MIB; SNMP agents process the requests and carry out the necessary operations to fulfill the management stations' requests.
A management station controls and monitors object instances on managed devices by using three basic SNMP operations: get, get-next, and set. Agents carry out and respond to these operations, and use a fourth SNMP operation, called a trap, to report unusual conditions or events to the management station.
SNMP agents are usually implemented as user processes that read information either from the kernel variables or from some sort of stable storage, such as files. Other user processes, like routed and gated, are sometimes employed to perform various network services. The SNMP agent needs to talk to these other processes to make their information available to the network management station.
The SMUX (SNMP Multiplexing) protocol defines a mechanism for communication between an SNMP agent and multiple user daemons (called SMUX peers). The SMUX protocol has the advantage of being vendor-independent: with SMUX, a single SNMP agent can be used to control and monitor devices from different vendors, regardless of how those vendors have implemented SMUX peers in their own products.
If you are unfamiliar with SNMP, you may wish to read the following information about it before you implement your SMUX peer: