It is used for both collecting information from and configuring the full range of network devices, including servers, printers, switches, hubs, routers, firewalls, wireless access points and individual workstations. A wide variety of information can be collected, ranging from a server's CPU (central processing unit) usage level to its chassis temperature.
SNMP software contains two main components: the manager and the agent. The former is generally installed on a system administrator's workstation, and the latter is installed on each client device that is being monitored. Communication between the two is accomplished by using UDP (user datagram protocol).
The advantage of using UDP instead of TCP (transmission control protocol), both of which operate at the transport layer of the seven-layer OSI (open systems interconnect) model, is that it has a low overhead and high speed and thus minimizes network bandwidth consumption. SNMP itself operates at the application layer (i.e., the top layer).
The first version, SNMPv1, unveiled in 1988, suffered from poor security, including the sending of authentication messages in cleartext (i.e., unencrypted). A second version, SNMPv2, was not widely adapted due to continuing security concerns. The most recent version, SNMPv3, was released in 2004.
Created November 7, 2005.