update() method

libSNMP works by polling. For this reason the update() method should be called frequently. This frequency depends on the timeout settings of your SNMP application, mainly. But I found out that polling every 100 milliseconds works good.

What happens when you call update()?

libSNMP updates upTime value and checks if any new SNMP request is available. If there is a new request, it responds. That's all :)