Monthly Archives: January 2018

OSPF RFC1583 vs RFC2328 compatibility

Best path selection:
RFC1583 – best path based solely on cost.
RFC2328 – Intra-area paths that use non-backbone areas are always the most preferred.

Can lead to the loops:

Summary metric:
RFC1583 – lowest metric of the componet routes
RFC2328 – highest metric of the components.

OSPF RFC1587 vs RFC3101 NSSA compatibility.

  1. Path selection
    a. Any type 5 LSA.
    b. A type-7 LSA with the P-bit set and the forwarding
    address non-zero.
    c. Any other type-7 LSA
    1. A Type-7 LSA with the P-bit set.
    2. A Type-5 LSA.
    3. The LSA with the higher router ID.
  2. The P-bit default is now defined as cleared.
  3. A new area configuration parameter, NSSATranslatorRole, is defined in Appendix D. It specifies whether or not an NSSA router will unconditionally translate Type-7 LSAs to Type-5 LSAs when acting as an NSSA border router.