Re: Draft-ietf-spring-network-programming ipv6 addressing architecture - was draft-ietf-6man-segment-routing-header-26 violating RFC4291, IPv6 Addressing Architecture?

[[e-mail]]

IP addresses have been used outside of the strict "identifiers for interfaces".
Apart from being used for routing, as a locator and as an identifier of course.
Load-balancers / addresses for a service, NAT, NPT66, NAT66, MAP-E/T, anycast addresses...
I am sure there are plenty others.

Unless Andrew can justify the "better result that works for everyone",
I do not believe rehashing the architectural properties of IP addresses serves any useful purpose.

Best regards,
Ole

> On 12 Mar 2020, at 09:26, Andrew Alston <[e-mail]> wrote:
> 
> Brian,
>  
> Let me clarify a few things – for my own understanding – I am happy to be wrong here, and if I am just let me know (while what I am writing may come across as statements, it was easiest to write that way, consider the statements clarification questions) –
>  
> Firstly – let us consider the RFC8402 argument for a second – though I think we should probably consider this separately.  In reference to RFC8402 this draft states – in section 3:
>  
> When an SRv6 SID is in the Destination Address field of an IPv6
>    header of a packet, it is routed through an IPv6 network as an IPv6
>    address.
>  
> So – we establish that indeed – SRv6 SID’s are IPv6 addresses – there is no two ways about it – they go into the destination field.  This is contrary to what Robert argued in an email found at https://mailarchive.ietf.org/arch/msg/spring/u1AzYFpDe-AhIxXdih2BEIz65Bk/
>  
> Now, lets look at this draft specifically in reference to RFC4291.
>  
> Section 2 of RFC4291 states that IPv6 addresses are identifiers for interfaces and sets of interfaces – where an interface is defined in RFC2460 as a “node’s attachment to a link”.  This document creates SID’s that have no binding to any interface.  Section 3 of the NP draft explicitly refers to lookups that lookup SID’s (which we have already established are addresses) that have no interface bindings.
>  
> In section 3.1 – this talks about the Locator – this is entirely compliant with section 2.5 of RFC4291 – however – the function and arguments section of this – have no relation to interface ID’s – it is debatable if this is as a result of problems in RFC8402 or indeed, potentially both drafts – since it is this document that explicitly creates these function and argument sections independently of RFC8402 in section 3.1.
>  
> Indeed RFC3587 states in section 3:
>  
> [ARCH] also requires that all unicast addresses, except those that
>    start with binary value 000, have Interface IDs that are 64 bits long
>    and to be constructed in Modified EUI-64 format.  The format of
>    global unicast address in this case is:
>  
>  
> I fail to see how defining a function and arguments in the way this document describes are compliant with this.  Now, it can also be argued that there are many implementations that violate these specifications – Linux allows you to bind entire /64s to loopback addresses, however, I would argue that it is a very different case for an implementation to violate the specification as for an RFC to violate the specification and make it into a standard.
>  
> I will also note and acknowledge that some may think that I am being pretty pedantic here – but considering the context and the claims floating around about what other RFC’s say and don’t say – perhaps its time to start examining this whole thing with a fine tooth comb so that we can end up with a better result that works for everyone and doesn’t lead to unintended consequences.
>  
> Thanks
>  
> Andrew
>  
>  
>  
> From: Brian E Carpenter <[e-mail]> 
> Sent: Thursday, 12 March 2020 00:30
> To: Andrew Alston <[e-mail]>; Darren Dukes (ddukes) <[e-mail]>; Ron Bonica <rbonica=[e-mail]>
> Cc: [e-mail]; 6man WG <[e-mail]>
> Subject: Re: Draft-ietf-spring-network-programming ipv6 addressing architecture - was draft-ietf-6man-segment-routing-header-26 violating RFC4291, IPv6 Addressing Architecture?
>  
> On 12-Mar-20 09:53, Andrew Alston wrote:
> > Hi Spring WG
> > 
> >  
> > 
> > On the basis of the below – I must conclude that the issues relating the SID/IPv6 semantics have indeed not been dealt with by the spring working group in the context of the network programming draft – and I would now like to raise those issues in the context of that draft – and the fact that draft-ietf-spring-network-programming violates the address semantic specifications of RFC4291.
> 
> I really think that this is subsidiary to RFC 8402 (a Proposed Standard):
> 
> SR can be applied to the IPv6 architecture with a new type of routing
> header called the SR Header (SRH) [IPv6-SRH]. An instruction is
> associated with a segment and encoded as an IPv6 address. An SRv6
> segment is also called an SRv6 SID. An SR Policy is instantiated as
> an ordered list of SRv6 SIDs in the routing header.
> 
> I don't see anything in the SRH draft or the network-programming draft
> that is not within that definition. Whether RFC 8402 contravenes RFC 4291
> is worth discussing, I guess. The latter says:
> 
> IPv6 addresses of all types are assigned to interfaces, not nodes.
> An IPv6 unicast address refers to a single interface. Since each
> interface belongs to a single node, any of that node's interfaces'
> unicast addresses may be used as an identifier for the node.
> 
> However, I can't find anything in RFC 4291 that forbids addresses
> having semantic meanings rather than being pure locators. It goes
> against one of my design prejudices, but I can't find anything
> resembling "Encoding semantics in address bits considered harmful"
> in the RFCs.
> 
> In reality, there are lots of operational practices that amount to
> giving semantic meanings to address bits.
> 
> Brian
> 
> > 
> >  
> > 
> > Can we please have a proper discussion on this
> > 
> >  
> > 
> > Thanks
> > 
> >  
> > 
> > Andrew
> > 
> >  
> > 
> >  
> > 
> > *From: *"Darren Dukes (ddukes)" <[e-mail]>
> > *Date: *Wednesday, 11 March 2020 at 22:03
> > *To: *Ron Bonica <rbonica=[e-mail]>
> > *Cc: *Andrew Alston <[e-mail]>, 6man WG <[e-mail]>
> > *Subject: *Re: draft-ietf-6man-segment-routing-header-26 violating RFC4291, IPv6 Addressing Architecture?
> > 
> >  
> > 
> > Hi Ron, I made no comment in this thread on draft-ietf-spring-network-programming.
> > 
> >  
> > 
> > Darren
> > 
> > 
> > 
> > On Mar 11, 2020, at 2:55 PM, Ron Bonica <rbonica=[e-mail] <mailto:rbonica=[e-mail]>> wrote:
> > 
> >  
> > 
> > Darren,
> > 
> >  
> > 
> > Didn’t we agree to close issue 66 because draft-ietf-6man-segment-routing header contains no text regarding SID/IPv6 address semantics. If that’s the case, how can you say that closing issue 66 implies WG consensus around SID/IPv6 address semantic proposed in draft-ietf-6man-network-programming?
> > 
> >  
> > 
> >                                                                                        Ron
> > 
> >  
> > 
> >  
> > 
> >  
> > 
> > Juniper Business Use Only
> > 
> > *From:* ipv6 <[e-mail] <mailto:[e-mail]>> *On Behalf Of *Darren Dukes (ddukes)
> > *Sent:* Tuesday, March 10, 2020 12:07 PM
> > *To:* [e-mail] <mailto:[e-mail]> <[e-mail] <mailto:[e-mail]>>
> > *Cc:* 6man WG <[e-mail] <mailto:[e-mail]>>
> > *Subject:* Re: draft-ietf-6man-segment-routing-header-26 violating RFC4291, IPv6 Addressing Architecture?
> > 
> >  
> > 
> > Hi Andrew please see issue #66 for the closure record. 
> > 
> >  
> > 
> > https://trac.ietf.org/trac/6man/ticket/66<https://urldefense.com/v3/__https:/trac.ietf.org/trac/6man/ticket/66__;!!NEt6yMaO-gk!RN-QFuaCraX6vU74Vusek5FlDyBGgfC2Teh1Vz40nw0PBhWdPtA-SA3t_rxaFg4_$>
> > 
> >  
> > 
> > Darren
> > 
> >  
> > 
> > On Mar 9, 2020, at 3:18 PM, Andrew Alston <[e-mail] <mailto:[e-mail]>> wrote:
> > 
> >  
> > 
> > Hi Darren
> > 
> >  
> > 
> > >  Hi Mark, the working group discussed the
> > 
> >  > association with RFC4291 and closed it with
> > 
> >  > the text in the document.
> > 
> >  
> > 
> > Can we get a reference to these discussions please - would just be useful to back and refresh memories and wasn’t able to find them
> > 
> >  
> > 
> > Thanks
> > 
> >  
> > 
> > Andrew
> > 
> >  
> > 
> > 
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