The mplsFrrFacilityDBTable provides information about the fast-reroute database. Each entry belongs to a protected interface, protecting backup tunnel, and protected tunnel. MPLS interfaces defined on this node are protected by backup tunnels and are indicated by the index mplsFrrFacilityProtectedIfIndex. If the interface index is set to 0, this indicates that the remaining indexes apply to all configured protected interfaces. Note that all objects in this table are read-only, and if new objects are added to this table, they should also be read-only. It is recommended that ifIndex persistence be enabled across re-initializations. If persistence is not implemented, then the value of mplsFrrFacilityProtectedIfIndex in this table cannot be guaranteed across restarts and all entries in this table MUST NOT be persistent, or the values of mplsFrrFacilityProtectedIfIndex MUST be reconstructed on restart. It is recommended that entries in this table be persistent across reboots. The protecting tunnel is indicated by the index mplsFrrFacilityProtectingTunnelIndex and represents a valid mplsTunnelEntry. Note that the tunnel instance index of the protecting tunnel may be set to 0, which indicates the tunnel head interface for the protecting tunnel, as per RFC 3812, but it may also be defined using the following semantics: - lower 16 bits : protected tunnel instance - higher 16 bits: must be all zeros