Hi Ron, I agree with Bob here. Section 4.2 pseudocode simply says an implementation would use a predetermined egress adjacency instead of performing a FIB lookup to find one. It specifies the SID processing, not the entire IPv6 data path.
It has no text that would indicate RFC4291 text on link-local addresses and routers would not apply. As a side note, every routing header currently defined (even those now deprecated) do not re-state the RFC4291 text. Thanks, Darren > On Dec 2, 2019, at 10:58 AM, Ron Bonica > <rbonica=40juniper....@dmarc.ietf.org> wrote: > > Bob, > > Before we debate presentation too much, we should let Pablo answer the > original question. Will the packet be dropped or forwarded? > > If the packet will be dropped, how is the reader of Section 4.2 to know this? > Normally, pseudocode is taken literally, and the pseudocode in Section 4.2 > suggests that the packet will be forwarded. > > One way to wiggle out of this problem is to include a sentence at the > beginning of Section 4 saying, "When the following pseudocode contradicts RFC > 4291 or 8200, RFCs 4291 and 8200 take precedence. > > > Ron > > > > > Juniper Business Use Only > > -----Original Message----- > From: Bob Hinden <bob.hin...@gmail.com> > Sent: Monday, December 2, 2019 10:47 AM > To: Ron Bonica <rbon...@juniper.net> > Cc: Bob Hinden <bob.hin...@gmail.com>; Mark Smith <markzzzsm...@gmail.com>; > SPRING WG <spring@ietf.org> > Subject: Re: [spring] SRv6 Network Programming and Link Local Source Addresses > > Ron, > >> On Dec 2, 2019, at 7:36 AM, Ron Bonica <rbon...@juniper.net> wrote: >> >> Bob, >> >> Take a look at Section 4.2. The pseudocode is pretty specific. > > Please explain. I don’t see that. > > Thanks, > Bob > > >> >> Ron >> >> >> >> Juniper Business Use Only >> >> -----Original Message----- >> From: Bob Hinden <bob.hin...@gmail.com> >> Sent: Sunday, December 1, 2019 5:56 PM >> To: Ron Bonica <rbon...@juniper.net> >> Cc: Bob Hinden <bob.hin...@gmail.com>; Mark Smith <markzzzsm...@gmail.com>; >> SPRING WG <spring@ietf.org> >> Subject: Re: [spring] SRv6 Network Programming and Link Local Source >> Addresses >> >> Ron, >> >>> On Dec 1, 2019, at 2:47 PM, Ron Bonica <rbon...@juniper.net> wrote: >>> >>> Mark, Bob, >>> >>> Yes, I agree that routers should not forward packets with link local source >>> addresses. >> >> or Destination addresses. >> >>> >>> Pablo, >>> >>> Maybe we should update section 4.2 of the network programming draft to >>> reflect this? >> >> I was thinking that unless network programming has text that might cause one >> to think it overrides the defined behavior from rfc4291 for link-local >> addresses, I am not sure it has to be mentioned. >> >> Bob >> >> >>> >>> Ron >>> >>> >>> From: Mark Smith <markzzzsm...@gmail.com> >>> Sent: Sunday, December 1, 2019 5:31 PM >>> To: Bob Hinden <bob.hin...@gmail.com> >>> Cc: Ron Bonica <rbon...@juniper.net>; SPRING WG <spring@ietf.org> >>> Subject: Re: [spring] SRv6 Network Programming and Link Local Source >>> Addresses >>> >>> >>> >>> On Mon, 2 Dec 2019, 08:35 Bob Hinden, <bob.hin...@gmail.com> wrote: >>> Ron, >>> >>>> On Nov 30, 2019, at 12:36 PM, Ron Bonica >>>> <rbonica=40juniper....@dmarc.ietf.org> wrote: >>>> >>>> Pablo, >>>> >>>> >>>> >>>> Consider the packet (SA,DA) (S3, S2, S1; SL) where: >>>> >>>> >>>> >>>> • SA is link-local (fe80) >>>> • DA, S3, S2, and S1 are all END.X >>>> >>>> >>>> Section 4.2 suggests that this packet will be delivered over multiple hops >>>> to its destination, regardless of its link-local source address. >>> >>> I would think that RFC2460 Section 2.5.6. "Link-Local IPv6 Unicast >>> Addresses” covers this: >>> >>> Link-Local addresses are for use on a single link. Link-Local >>> addresses have the following format: >>> >>> | 10 | >>> | bits | 54 bits | 64 bits | >>> +----------+-------------------------+----------------------------+ >>> |1111111010| 0 | interface ID | >>> +----------+-------------------------+----------------------------+ >>> >>> Link-Local addresses are designed to be used for addressing on a >>> single link for purposes such as automatic address configuration, >>> neighbor discovery, or when no routers are present. >>> >>> Routers must not forward any packets with Link-Local source or >>> destination addresses to other links. >>> >>> I think that's RFC4291. >>> >>> RFC4007, "IPv6 Scoped Address Architecture" does too, more generally and >>> probably more formally, in particular section 9, "Forwarding". >>> >>> Regards, >>> Mark. >>> >>> >>> >>> Bob >>> >>> >>>> >>>> >>>> >>>> Is this the case? >>>> >>>> >>>> >>>> Ron >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> Juniper Business Use Only >>>> _______________________________________________ >>>> spring mailing list >>>> spring@ietf.org >>>> https://www.ietf.org/mailman/listinfo/spring >>> >>> _______________________________________________ >>> spring mailing list >>> spring@ietf.org >>> https://www.ietf.org/mailman/listinfo/spring >>> >>> Juniper Business Use Only > _______________________________________________ > spring mailing list > spring@ietf.org > https://www.ietf.org/mailman/listinfo/spring _______________________________________________ spring mailing list spring@ietf.org https://www.ietf.org/mailman/listinfo/spring
