Also, given particule conditions, the MD can send a 'trap' to the MS, alerting the MS to some condition. These queries and responses are referred to as 'polling'. The MS 'polls' the MD for information. This communication is referred to as a 'trap'. The first version, SNMP v1, is probably the most widely used version.
Some systems seem to install and enable SNMP with little or no input from the user.
Cisco routers simply require that the entry for SNMP be marked yes or no, for example. As I said, the MIB is essentially a database of managed information. Each piece of information is referenced by an object identifier or 'OID'. One of the configuration options for SNMP is something called the 'community string'. Cisco and Microsoft's versions come to mind.