I decided to monitor my interfaces using net-snmp and rrdtool
replacing the old mrtg server. Now, just wondering... When I create an
MRTG configuration, I see it scanning lots of things and it takes some
time to create the cfg file.

I created an interface that uses snmpget and snmpwalk to get the
available ports and poll the information, and all the process taks
about 1 to 2 seconds.

Am I losing something here? What do MRTG do that takes so long that i
am not doing?