Using 64-bit counters for traffic accounting in net-snmp

Hello,

I'm trying to learn how to setup net-snmp at home on my personal Linux
computer. I have been successful so far and I can snmpwalk my MIBs
without problem.

During my research on the web about net-snmp, I've seen various posts
stating that it is possible to do IP accounting with net-snmp.
Particularly, to overcome the fact that the current Linux kernel is
limited to 32-bit byte counters for interface statistics.

Having tried to google on the subject, I am unable to find the way to
use 64-bit IP accounting with net-snmp under Linux.

So far what I'm aware of is that in share/snmp/IF-MIB.txt, there is a
mention of SNMP objects called ifHCInOctets/ifHCOutOctects of type
Counter64. I haven't found how to make them active when loading the
agent. snmpwalk shows a list of objects in the IF MIB, but not those
specific ones.

How can I setup 64-bit IP accounting using net-snmp under Linux?

Any tip/pointer would be appreciated.

Thanks.