vRtrIgmpGrpIfHostGrpMode is based on the type of membership report(s)
received on the SAP for the group. In the 'include' mode,
reception of packets sent to the specified multicast address is
requested only from those IP source addresses listed in the
source-list parameter of the IGMP membership report.
In 'exclude' mode, reception of packets sent to the given multicast
address is requested from all IP source addresses except those listed
in the source-list parameter.
vRtrIgmpGrpIfSapGrpSrcTable lists the sources corresponding to this group,
if any.