The VRFs default polling group is used by MPLS Manager to monitor the availability of VRFs. MPLS Manager monitors the availability by monitoring the VRFs that are discovered on PE or multi-VRF CE devices.
The VRFs polling group has a default setting and an optional setting:
VRF SNMP Setting (default)
VRF External Setting (optional)
The two settings are mutually exclusive, meaning that only one or the other (but not both) can be specified for a VRFs polling group at any given time.