Windows hosts still use 32-bit MIB-2 counters for Interface Performance.
Regarding the Gigabyte Interfaces, the following note is from the
tpmgr-param.conf configuration file:
If InHCOctets/IfMIB table[64bit octet] counters are NULL and FallbackInterfaceMonitoringToMIB2 is TRUE and if below FLAG is set to TRUE, then system will force all Host GB interface to be instrumented by MIB2. This option works only for HOST interfaces. If Customer wants to monitor Host GB interface then he can enable this option, if he feels that their Host interfaces ifTable[MIB2/32bit] counters will not roll in the successive polling period.