Using SNMP
Simple Network Management Protocol (SNMP) is perhaps the oldest and most used protocol to gather management information from devices. The SNMP specification was first published in 1998 in RFC 2261 and was designed to be simple and fast.
SNMP agents and managers
SNMP defines two identities:
- The manager (or server)
- The agent
The agent is normally a network device and the manager is a network management system.
SNMP uses UDP and TCP as transport protocols with ports 161 and 162. The UDP port 161 is used to gather or set information in an on-demand manner, where the manager sends the request to the agent. The UDP port 162 is used asynchronously without a request from the manager. The agent sends UDP packets to the server whenever necessary. This method is called an SNMP trap and is used to send unsolicited messages, such as alarms or threshold-level breaches.
An SNMP MIB
As described in Chapter 1, a Management Information Base (MIB) is used...
