_(INVALID_ADDRESS_FAMILY, -97, "Invalid address family") \
_(INVALID_SUB_SW_IF_INDEX, -98, "Invalid sub-interface sw_if_index") \
_(TABLE_TOO_BIG, -99, "Table too big") \
-_(CANNOT_ENABLE_DISABLE_FEATURE, -100, "Cannot enable/disable feature")
+_(CANNOT_ENABLE_DISABLE_FEATURE, -100, "Cannot enable/disable feature") \
+_(BFD_EEXIST, -101, "Duplicate BFD session") \
+_(BFD_NOENT, -102, "No such BFD session")
typedef enum
{