One correction: “It should be expanded further” should be “it shouldn’t be expanded further”
Aijun Wang China Telecom > On Oct 13, 2022, at 18:53, Aijun Wang <[email protected]> wrote: > > Hi, Acee and Peter: > > I think you all misunderstood the intent of his scenario. > The correct understanding are the followings: > 1) When aggregate route is configured in the ABR, the specified detail route > should be withdrawn. > 2) ABR can withdraw the advertised LSA that describes the specific detail > route, via premature mechanism(MaxAge or LSInfinity, the former is preferred > according to RFC2328) > 3) But, withdrawn such specific LSA doesn’t mean the corresponding detail > route unreachable——This destination can be reached via the aggregate route > advertised by ABR instead. > > This is the original usage of LSInfinity defined in RFC2327. It should be > expanded further. > > How to apply it in RFC8362 is another issue, as indicated my responses in > another thread. > > In summary, again, we should constrain or depreciate the confusion usages of > LSInfinity. > > Aijun Wang > China Telecom > >> On Oct 13, 2022, at 18:07, Acee Lindem (acee) >> <[email protected]> wrote: >> >> Hi Zhibo, >> >> On 10/13/22, 2:26 AM, "Lsr on behalf of Huzhibo" <[email protected] on >> behalf of [email protected]> wrote: >> >> Hi LSR: >> >> LSInfinity >> The metric value indicating that the destination described by an >> LSA is unreachable. Used in summary-LSAs and AS-external-LSAs >> >> I want to clarify the meaning of unreachable in LSifinity, >> Assume that a node advertise specific route of 1.1.1.1/32, and an >> aggregate route 1.1.0.0/16 is configured. >> This node should premature aging of the 1.1.1.1/32 LSA. >> If this node using LSInfinity metric instead of prematuring aging, route >> 1.1.1.1/32 is still reachable. >> Therefore, the "unreachable" described by LSifinity is not really >> unreachable. >> >> If your OSPF implementation includes unreachable LSAs in the summary cost >> computation, it is indeed broken. >> >> Thanks, >> Acee >> >> Thanks >> Zhibo hu >> >>> -----Original Message----- >>> From: Lsr [mailto:[email protected]] On Behalf Of Peter Psenak >>> Sent: Wednesday, October 5, 2022 5:32 PM >>> To: [email protected] >>> Subject: [Lsr] RFC 8362 and LSInfinity >>> >>> Hi Folks, >>> >>> metric of LSInfinity (0xFFFFFF) has been defined in RFC2328: >>> >>> LSInfinity >>> The metric value indicating that the destination described by an >>> LSA is unreachable. Used in summary-LSAs and AS-external-LSAs >>> as >>> an alternative to premature aging (see Section 14.1). It is >>> defined to be the 24-bit binary value of all ones: 0xffffff. >>> >>> RFC5340 inherited it from RFC2328: >>> >>> Appendix B. Architectural Constants >>> >>> Architectural constants for the OSPF protocol are defined in >>> Appendix >>> B of [OSPFV2]. The only difference for OSPF for IPv6 is that >>> DefaultDestination is encoded as a prefix with length 0 (see >>> Appendix A.4.1). >>> >>> Both RFC2328 and RFC5340 used 16 bits metric for intra-area prefix >>> reachability, so the LSInfinity was not applicable for intra-area prefixes. >>> >>> RFC8362 defines 24-bit metric for all prefix reachability TLVs - >>> Intra-Area-Prefix TLV, Inter-Area-Prefix TLV, External-Prefix TLV. >>> Al > > _______________________________________________ > Lsr mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/lsr _______________________________________________ Lsr mailing list [email protected] https://www.ietf.org/mailman/listinfo/lsr
