Back pocket bash script to poll specific oids at a high rate. This allows polling the in and out bits of a router interface with out beating up the device. The focus is on simplicity and minimal dependencies. All you need is bash and snmpget.
https://www.iana.org/assignments/smi-numbers/smi-numbers.xhtml#smi-numbers-24
http://www.net-snmp.org/docs/mibs/interfaces.html
https://github.com/hardaker/net-snmp/blob/master/mibs/IF-MIB.txt