Hi Dirk, Please check inline below again with KT2 and I am trimming to limit to the open discussion point.
On Thu, Aug 11, 2022 at 9:28 PM Goethals, Dirk (Nokia - BE/Antwerp) < [email protected]> wrote: > KT> The Attached (A/LA) flag was used in RFC8666/8667 for the propagation > of SRMS advertisements. The question is if that is required or relevant for > SRv6 Locators. There is no harm/issue with introducing a new Attached flag > (even if I am not sure of its use) and renaming the current Anycast flag to > something else (e.g., AC?). But perhaps I might be missing something and if > so, please clarify. > > > > > *[DG>] I was referring to the text mentioned in RFC8362 chapter 3.1 Prefix > Options Extensions, for the reasons as mentioned in yellow below. As such, > it would be equally useful for the ABR’s * > > *local ‘node-locators’, unless the ABR is advertising these local > ‘node-locators’ in all area’s as * > > *route-type 1, is that the plan?* > > > > The prefix options are extended from Appendix A.4.1.1 > <https://datatracker.ietf.org/doc/html/RFC8362#appendix-A.4.1.1> [OSPFV3 > <https://datatracker.ietf.org/doc/html/RFC8362#ref-OSPFV3>]. The > > applicability of the LA-bit is expanded and it SHOULD be set in > > Inter-Area-Prefix-TLVs and MAY be set in External-Prefix-TLVs when > > the advertised host IPv6 address, i.e., PrefixLength = 128, is an > > interface address. In RFC 5340 > <https://datatracker.ietf.org/doc/html/rfc5340>, the LA-bit is only set > in Intra- > > Area-Prefix-LSAs (Section 4.4.3.9 in [OSPFV3 > <https://datatracker.ietf.org/doc/html/RFC8362#ref-OSPFV3>]). This will > allow a > > stable address to be advertised without having to configure a > > separate loopback address in every OSPFv3 area. > > > KT2> I now see your point and it is good that you brought that out. In my view, the SRv6 locator is associated with the node and not specific to an area (though its advertisement could be potentially limited to specific areas by policy - e.g., suppressed for summarization). So, it would make things simpler if the SRv6 Locator of an ABR were advertised as Type 1 (i.e. Intra-Area) in all the attached areas. I believe the Type-1 advertisement handles some scenarios better than the attached flag with Type 3. However, if you feel strongly about this, we can also include the LA-flag to enable the association of SRv6 Locator to a specific area and then advertise as Inter-Area (with LA-flag) in other attached areas. Thanks, Ketan > > > Thanks, > > Ketan > > > > > > Regards, > > Dirk > > > >
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