P- Bit is dealt in LSAs in OSPF. External routes are received as Type - 7 LSAs in NSSA router. Type 7 LSAs are confined to only specific area it is received . To further distribute the external Type 7 LSAs are translated into Type 5 LSAs. The P-bit in the type 7 LSA Options field indicates whether the type 7 LSA should be translated. Only those LSAs with the P-bit set are translated into Type 5 LSAs so that the external route can be spread to other areas.