Re: [spring] IPv6 Addresses and SIDs

On Mon, Oct 14, 2019 at 10:12 AM Gyan Mishra <hayabusagsm@gmail.com> wrote:

>
>
> On Mon, Oct 14, 2019 at 1:45 AM Wang, Weibin (NSB - CN/Shanghai) <
> weibin.wang@nokia-sbell.com> wrote:
>
>> Hi Ron:
>>
>>
>>
>> Make sense, If there is a dedicated IPv6 block for SRv6 SID within SRv6
>> domain, then trouble situation you described does NOT occur, because the
>> IPv6 address covered within SRv6 SID prefix does not be involved ICMPv6 ND
>> protocol, because they are not configured under IP interfaces connected to
>> “Link”.  I also think that the authors of NET-PGM draft have indicated that
>> SRv6 SID has a separate IPv6 block in their Draft, but they don’t yet
>> clearly stated which IPv6 block will be used for it.
>>
>>
>>
>>  [Gyan] I agree with what you are saying that if we allocate a separate
>> /64 block GUA or ULA for SID for each node within the SR domain and that is
>> separate from interface addressing ranges and is completely dedicated to
>> SID.  So this would prevent any conflict with ND NS/NA processing.  Makes
>> sense.  We are addressing the violation to the 6MAN RFC 8200 in draft below
>> which was rewritten  and does look better with the addition of
>> encapsulation but really need to provide an additional IPv6 encapsulation
>> every time a EH is inserted "in flight" to be 100% compliant with the IPv6
>> specification.   Since SRv6  ubiquitous in nature and can be used for any
>> implementation where traffic engineering is necessary when you go
>> inter-domain between administrative control it maybe difficult to enforce
>> or have either the PSP & USP occur outside of the originating SRv6 domain
>> that inserted the 1st EH header which the main use case that would be
>> difficult is the "internet" use case.  If we cannot come up with a solution
>> for that we would have to exclude the internet or any inter-domain SRv6
>> implementations from using SRv6 from a standards track perspective.
>>
>
>
> https://datatracker.ietf.org/doc/draft-voyer-6man-extension-header-insertion/
>
>
>> --------------------------------------
>>
>> *Cheers !*
>>
>>  [Gyan]  Spring WG  -??  Because SRv6 uses the same IPv6 data plan as
>> "Business as Usual" NORMAL IPv6 traffic use case of the "internet"  so
>> the an "SRv6 enabled router" that has the code that supports SRv6 has the
>> software feature to perform the PSP & USP but lets say the packet hits a
>> node that does not support SRv6 then the PSP & USP won't occur and all the
>> EH headers inserted for SRv6 routing header type 4 will remain in the
>> packet to the end destination.   How do we deal with this issue.
>>
>
>>
>> *WANG Weibin  *
>>
>>
>>
>> *From:* spring <spring-bounces@ietf.org> *On Behalf Of *Ron Bonica
>> *Sent:* 2019年10月14日 9:23
>> *To:* Robert Raszuk <robert@raszuk.net>
>> *Cc:* SPRING WG List <spring@ietf.org>
>> *Subject:* Re: [spring] IPv6 Addresses and SIDs
>>
>>
>>
>> Robert,
>>
>>
>>
>> Yeah, there were a few typos in my original message. What I meant to say
>> was:
>>
>>
>>
>>    - If a /64 contains a SID, it MUST NOT contain any addresses that
>>    represent interfaces.
>>    - If a /64 contains an address that represents an interface, it MUST
>>    NOT contain SIDs.
>>
>>
>>
>> If we don’t do this, we have to specify how nodes behave when they
>> receive ICMPv6 NS messages in which the target is:
>>
>>
>>
>>    - A locally instantiated SID
>>    - A SID learned from the IGP
>>
>>
>>
>>                                                                       Ron
>>
>>
>>
>>
>>
>> *From:* Robert Raszuk <robert@raszuk.net>
>> *Sent:* Sunday, October 13, 2019 6:57 PM
>> *To:* Ron Bonica <rbonica@juniper.net>
>> *Cc:* SPRING WG List <spring@ietf.org>
>> *Subject:* Re: IPv6 Addresses and SIDs
>>
>>
>>
>> Hi Ron,
>>
>>
>>
>> /64 prefix is a pile of addresses ... if someone would be to follow your
>> suggestion I could not allocate some blocks of that prefix on R1, then some
>> other blocks on R2 then yet more on my servers.
>>
>>
>>
>> You said:
>>
>>
>>
>> *“With a /64, if one /128 represents an IPv6 interface, as described in
>> RFC 4291, all /128 MUST either:*
>>
>>
>>
>>    - *Represent an IPv6 interface, as described in RFC 4291, or*
>>    - *Be unassigned”*
>>
>>
>>
>> Maybe you meant to say something else:
>>
>>
>>
>> *“When a /64 is used as SRv6 locator prefix, if one /128 represents an
>> IPv6 interface, as described in RFC 4291, all /128 MUST either:*
>>
>>
>>
>>    - *Represent an IPv6 interface, as described in RFC 4291, or*
>>    - *Be unassigned”*
>>
>> But then you sent this to SPRINT indicating that 6MAN should be the
>> audience :).
>>
>>
>>
>> Best,
>> R.
>>
>>
>>
>>
>>
>> On Mon, Oct 14, 2019 at 12:45 AM Ron Bonica <rbonica@juniper.net> wrote:
>>
>> Robert,
>>
>>
>>
>> I’m having a hard time understanding exactly how I have violated the
>> longest match principle. Could you provide:
>>
>>
>>
>>    - A pointer to a statement of the longest match principle
>>    - A few words regarding how I have violated it
>>
>>
>>
>>                                                               Ron
>>
>>
>>
>>
>>
>> *From:* Robert Raszuk <robert@raszuk.net>
>> *Sent:* Sunday, October 13, 2019 5:24 PM
>> *To:* Ron Bonica <rbonica@juniper.net>
>> *Cc:* SPRING WG List <spring@ietf.org>
>> *Subject:* IPv6 Addresses and SIDs
>>
>>
>>
>> Hi Ron,
>>
>>
>>
>> I disagree.
>>
>>
>>
>> Your suggestion violates longest prefix match principle in routing.
>>
>>
>>
>> It is huge waist of address space and is not specific to IPv6 at all.
>>
>>
>>
>> Let me describe the deployment case where your suggestion would cause it
>> to break:
>>
>>
>>
>> I have /64 prefix where a few  /128s from that space I allocate to local
>> interfaces making it a local v6 destinations on those nodes.
>>
>>
>>
>> However in the spirit of CIDR I still want to to use some blocks of that
>> space - say  /126 or /124 as blocks which I only use to trigger local NAT
>> as per rfc6296. And NAT does not require local address to be a destination
>> address so it would be a big disservice to kill such deployment option.
>>
>>
>>
>> Many thx,
>> R.
>>
>>
>>
>>
>>
>> On Sun, Oct 13, 2019 at 10:59 PM Ron Bonica <rbonica=
>> 40juniper.net@dmarc.ietf.org> wrote:
>>
>> Folks,
>>
>>
>>
>> I think that we need a global rule that says:
>>
>>
>>
>> “With a /64, if one /128 represents an IPv6 interface, as described in
>> RFC 4291, all /128 MUST either:
>>
>>
>>
>>    - Represent an IPv6 interface, as described in RFC 4291, or
>>    - Be unassigned”
>>
>>
>>
>> The 6man WG will need to make such a statement since it owns RFC 4291.
>>
>>
>>
>>                                                              Ron
>>
>>
>>
>> Juniper Business Use Only
>>
>>
>>
>> Juniper Business Use Only
>>
>> _______________________________________________
>> spring mailing list
>> spring@ietf.org
>> https://www.ietf.org/mailman/listinfo/spring
>>
>
>
> --
>
> Gyan S. Mishra
>
> IT Network Engineering & Technology
>
> Verizon Communications Inc. (VZ)
>
> 13101 Columbia Pike FDC1 3rd Floor
>
> Silver Spring, MD 20904
>
> United States
>
> Phone: 301 502-1347
>
> Email: gyan.s.mishra@verizon.com
>
> www.linkedin.com/in/networking-technologies-consultant
>
>

-- 

Gyan S. Mishra

IT Network Engineering & Technology

Verizon Communications Inc. (VZ)

13101 Columbia Pike FDC1 3rd Floor

Silver Spring, MD 20904

United States

Phone: 301 502-1347

Email: gyan.s.mishra@verizon.com

www.linkedin.com/in/networking-technologies-consultant