64bit SNMP Interface Counters

[olu2]

Has anyone had any luck getting 64bit SNMP counters working to monitor interface traffic?
I'm currently running 2.2.5-RELEASE (amd64)

When trying to run the 64bit walk:

$ snmpwalk -v 2c -c public 10.1.2.1 1.3.6.1.2.1.31.1.1.1.6
IF-MIB::ifHCInOctets = No Such Instance currently exists at this OID

Example of the 32bit counters working:

$ snmpwalk -v 2c -c public 10.1.2.1 1.3.6.1.2.1.2.2.1.10
IF-MIB::ifInOctets.1 = Counter32: 0
IF-MIB::ifInOctets.2 = Counter32: 0
IF-MIB::ifInOctets.3 = Counter32: 0
IF-MIB::ifInOctets.4 = Counter32: 0
IF-MIB::ifInOctets.5 = Counter32: 3415920844
IF-MIB::ifInOctets.6 = Counter32: 1566036770
IF-MIB::ifInOctets.7 = Counter32: 6731179
IF-MIB::ifInOctets.8 = Counter32: 18832652
IF-MIB::ifInOctets.9 = Counter32: 210993916
IF-MIB::ifInOctets.10 = Counter32: 1684635