Re: [lisp] [spring] IPv6-compressed-routing-header-crh
Robert Raszuk <robert@raszuk.net> Thu, 18 April 2019 14:30 UTC
Return-Path: <robert@raszuk.net>
X-Original-To: lisp@ietfa.amsl.com
Delivered-To: lisp@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 0482C1200DF for <lisp@ietfa.amsl.com>; Thu, 18 Apr 2019 07:30:50 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.011
X-Spam-Level:
X-Spam-Status: No, score=-0.011 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, HTML_MESSAGE=0.001, HTTPS_HTTP_MISMATCH=1.989, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=unavailable autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=raszuk.net
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Ty_z4W2xCW1P for <lisp@ietfa.amsl.com>; Thu, 18 Apr 2019 07:30:44 -0700 (PDT)
Received: from mail-qt1-x842.google.com (mail-qt1-x842.google.com [IPv6:2607:f8b0:4864:20::842]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 36CD6120418 for <lisp@ietf.org>; Thu, 18 Apr 2019 07:30:44 -0700 (PDT)
Received: by mail-qt1-x842.google.com with SMTP id f13so2004442qto.6 for <lisp@ietf.org>; Thu, 18 Apr 2019 07:30:44 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=raszuk.net; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=NTSQaZFa2Mf31wBt3okiQ/Q27njdUVfwUFFuDeOp8Js=; b=YffNL6byhw1UIwM90hlY5FNY4hKD9bN37u7VCRGJD87LePRrg8QqllJ1on+QlBwrQi Pm+1jI8CCUa7ZqA3rFlTh0C5jh6GhbdNoqxcghK44ysLrih9h9sFBtKQlUIoP5Ky2Qu5 B+GElSi8UebgqMYp5/zE4WmKDVgemR9aVyMRh1guxrCB3PY8ZEswEHJOVAw3jvLazx/q RXvMKIaefUk2JTpxD8zZWKiv+ectxJaKLKwXT373w2VR4uwsSXg8s8UIkhQjpEpBJXhd uS+OFJ+RzAb7mIpDkvMl8g00e4nWtRfBQavVbEM94llPZseqMyjQE900bntQj1S7EtoI ZHCw==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=NTSQaZFa2Mf31wBt3okiQ/Q27njdUVfwUFFuDeOp8Js=; b=eamk5p2VK3S3jatYv1UmE7Pi/3LkVQ4I1WLDQqJNYA/7Dpvln81YhdXkYtS+vwW5Gp ZkxKWdz7Z2b2fEGrOVDg+8gTTAGFYaV7SK69LSEd/PJl3e0hZA6YhhAbhyaLpl+Lc3Y1 VQO9Nb6TnI2+CmQQV9j10mtGQcFqXa3BRnSjp2K4IWosu1x57GzW8VElFqnpiKjavgCc SB5szMs9Xof0kxh5fR5mpJradfGmG6wy0vPzOrP/mEm1BL3u2JsUoQvlfI3NgVrsIuPl UYrWwCRnNI6VdQo9PDHezR9QuXfO8bLLYA4/Uf0zahmGnuLDiaGp27gEVXM1CLeAknZE ss8A==
X-Gm-Message-State: APjAAAV1moxQDPoSTCt4rXAmZTQX6kWXGnMHt9ZYlCtQmiE+EspTt/Q/ 6JK6iZIvU6o2IbKA8h0DMjw6hEvkoeZ7YZGITjQF0Q==
X-Google-Smtp-Source: APXvYqw4yTNZAXSfGFwSnSEXTxn5z8vhlMYOQMKgEFwKosdGnMrqBeRVRu3J7jaO/S3sEh58UHRupHO1kbxNV1dpHVA=
X-Received: by 2002:a0c:d1a6:: with SMTP id e35mr75379267qvh.174.1555597843154; Thu, 18 Apr 2019 07:30:43 -0700 (PDT)
MIME-Version: 1.0
References: <A881B89B-5E72-40CD-81F3-50396958A554@cisco.com> <BYAPR05MB4245D3F821D84847549FB6DAAE5A0@BYAPR05MB4245.namprd05.prod.outlook.com> <CA+b+ERmo9cPgCtnDgvkqNkFiLXdOJikWRLOKXM9NQfbNtJ__Zg@mail.gmail.com> <CAO42Z2yKmWub+maw4oVzaEY4HoHVszwOo4FQNCHT0uVkKFNwRw@mail.gmail.com> <CA+b+ERk+UiXg5Vtv-2kshkJ9VQMpMF22deFpKfGeMmqbBE9QtA@mail.gmail.com> <CAO42Z2yPi6wb85jh5es3feboJ5fOhr+iS8OraPjLD-rKTkNSQg@mail.gmail.com> <CAOj+MMHXWsXbBmByy8TWNfAWm0fKuiN6BDdGLzBgN7GRHkz+1A@mail.gmail.com> <CALx6S34FPPq9R=RAxhnPJRHT8z07htnC8banLkL2gU94Bz61hQ@mail.gmail.com> <CAO42Z2z+4JhObAktyd0KrULdwcrSkiFOD4cOVPt0QeVdHVES9A@mail.gmail.com> <CALx6S35Xnymc3oSKOX68bmtuWTH_6_Cd10FwjOd0db9TXVGp8Q@mail.gmail.com> <CAOj+MMG79BeMy2HgeS0WFs8+ZZzpNG77M8E7A4zbDjjKs7wG3Q@mail.gmail.com> <BYAPR05MB4245D2964D8F90A3A76356C0AE2A0@BYAPR05MB4245.namprd05.prod.outlook.com> <46DF565F-9A1A-4247-9A05-DE04396C8F5A@gmail.com> <BYAPR05MB4245A7C3E215FF0028FE9B06AE260@BYAPR05MB4245.namprd05.prod.outlook.com>
In-Reply-To: <BYAPR05MB4245A7C3E215FF0028FE9B06AE260@BYAPR05MB4245.namprd05.prod.outlook.com>
From: Robert Raszuk <robert@raszuk.net>
Date: Thu, 18 Apr 2019 16:30:29 +0200
Message-ID: <CAOj+MMGhU3bJtfQ4QjCeFiFpj+XkEhjnvU0MgO9bhNEvERN7Ew@mail.gmail.com>
To: Ron Bonica <rbonica@juniper.net>
Cc: Gyan Mishra <hayabusagsm@gmail.com>, Tom Herbert <tom@herbertland.com>, SPRING WG <spring@ietf.org>, "ipv6@ietf.org" <ipv6@ietf.org>, Dino Farinacci <farinacci@gmail.com>, "lisp@ietf.org list" <lisp@ietf.org>
Content-Type: multipart/alternative; boundary="000000000000dae3dc0586ced8de"
Archived-At: <https://mailarchive.ietf.org/arch/msg/lisp/lkOmWmkIk-a5dFgG-jjwv8xESNU>
Subject: Re: [lisp] [spring] IPv6-compressed-routing-header-crh
X-BeenThere: lisp@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: List for the discussion of the Locator/ID Separation Protocol <lisp.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/lisp>, <mailto:lisp-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/lisp/>
List-Post: <mailto:lisp@ietf.org>
List-Help: <mailto:lisp-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/lisp>, <mailto:lisp-request@ietf.org?subject=subscribe>
X-List-Received-Date: Thu, 18 Apr 2019 14:30:50 -0000
Hi Ron, I must observe that your analysis is incorrect. SIDs are not only used for TE or traffic steering purposes but what is even more interesting for various functions - for example NFV. So you need as much SIDs as possible imagination of your value add network functions - which will be different from those functions at the encap dst which as you indicate in other draft can be carried in destination options. That debate is still I think open. Thx, R. On Thu, Apr 18, 2019 at 4:02 PM Ron Bonica <rbonica@juniper.net> wrote: > Gyan, > > > > Let’s think about how a network operator might choose a SID size…. > > > > Assume that an MAN includes 100 routers. These routers are connected to > one another by infrastructure links. Each router has 20 or fewer > infrastructure links. > > > > The network operator might assign one loosely routes SID to each router. > These loosely routed SIDs have network-wide significance (i.e., the cannot > be reused). > > > > The network operator might also assign one strictly routed SID to each > link. The strictly routed SIDs have node-local significance only. They can > be reused from one node to another. > > > > So, in this case, the network operator only needs 120 SIDs. This fits in > eight bits with plenty of room for growth. > > > > Now consider another network that includes 30,000 routers. Each router is > connected to its peers by 200 infrastructure links or fewer. This network > would need 30,200 SIDs. This would fit in 16 bits. > > > > A **really big** network might require more than 32,000 SIDs. So, we > support a 32-bit SID. > > > > > Ron > > > > > > > > > > Juniper Internal > > *From:* Gyan Mishra <hayabusagsm@gmail.com> > *Sent:* Wednesday, April 17, 2019 10:00 PM > *To:* Ron Bonica <rbonica@juniper.net> > *Cc:* Robert Raszuk <robert@raszuk.net>; Tom Herbert <tom@herbertland.com>; > SPRING WG <spring@ietf.org>; ipv6@ietf.org; Dino Farinacci < > farinacci@gmail.com>; lisp@ietf.org list <lisp@ietf.org> > *Subject:* Re: [spring] IPv6-compressed-routing-header-crh > > > > > > I agree to make the SID align on word boundaries but I am thinking the > software should have hardware independence if at all possible. > > > > I think 32 bit is a reasonable size. > > > > > > Gyan S. Mishra > > IT Network Engineering & Technology Consultant > > Routing & Switching / Service Provider MPLS & IPv6 Expert > > www.linkedin.com/in/GYAN-MISHRA-RS-SP-MPLS-IPV6-EXPERT > <https://urldefense.proofpoint.com/v2/url?u=http-3A__www.linkedin.com_in_GYAN-2DMISHRA-2DRS-2DSP-2DMPLS-2DIPV6-2DEXPERT&d=DwMFaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF2EfpHcAwrDThKP8&m=7oInX5oGRmd36ozKW9gDLBfD4hBl0G89as-W-cNq90s&s=OVr9Tne6BBif0Ns2o9wbCzeNT3f1qK4Yq0tED0Ba6F8&e=> > > Mobile – 202-734-1000 > > > > Sent from my iPhone > > > On Apr 14, 2019, at 7:54 PM, Ron Bonica < > rbonica=40juniper.net@dmarc.ietf.org> wrote: > > Hi Robert, > > > > In order to make the CRH ASIC-friendly, we have the following constraints: > > > > - Support only a small handful of SID lengths > - If at all possible, make them align on word boundaries > > > > Currently, we support 8, 16 and 32 bytes. Do you see a reason why we > should support a length greater than 32? Is there some length less than 32 > that would be beneficial? > > > > Ron > > > > > > > > Juniper Internal > > *From:* spring <spring-bounces@ietf.org> *On Behalf Of *Robert Raszuk > *Sent:* Friday, April 12, 2019 6:13 PM > *To:* Tom Herbert <tom@herbertland.com> > *Cc:* SPRING WG <spring@ietf.org>; ipv6@ietf.org; Mark Smith < > markzzzsmith@gmail.com>; Dino Farinacci <farinacci@gmail.com>; > lisp@ietf.org list <lisp@ietf.org> > *Subject:* Re: [spring] IPv6-compressed-routing-header-crh > > > > Hi Tom, > > > > I already suggested this on March 30th ... > > > > *"**PS. But if you choose to go ahead with CRH I would highly advise to > make your CRH SID a variable length. "* > > > > No feedback/response was received from authors. > > > > Thx, > R. > > > > On Sat, Apr 13, 2019 at 12:09 AM Tom Herbert <tom@herbertland.com> wrote: > > On Fri, Apr 12, 2019 at 1:48 PM Mark Smith <markzzzsmith@gmail.com> wrote: > > > > Hi Tom, > > > > On Sat, 13 Apr 2019 at 00:26, Tom Herbert <tom@herbertland.com> wrote: > > > > > > On Sun, Mar 31, 2019 at 7:40 AM Robert Raszuk <robert@raszuk.net> > wrote: > > > > > > > > Hi Mark, > > > > > > > > > As MPLS SR SIDs are 20 bits, then rounding up to an octet boundary > and a 32 bit alignment, > > > > > I'd think 32 bit SIDs would be adequate to perform SR in an IPv6 > network. > > > > > > > > > > As 32 bit SIDs are also the same size as IPv4 addresses, that may > also create some opportunities to > > > > > leverage IPv4 support in existing protocols to suite carrying and > processing 32 bit SIDs with some, possibly > > > > > slight, modification. For example, perhaps IPv4 Address Family > support in OSPFv3 (RFC 5838) could be > > > > > somehow leveraged to suit SR. > > > > > > > > > > > > Thank you for describing your understanding of fundamentals of SR. > > > > > > > > I think SR while indeed started with the story of "less control > plane is good for you" now clearly has evolved into not only reduction of > control plane but what can be even more important to some users ability to > request specific behavior via programmed functions of network elements on a > per flow basis without actually per flow or per path signalling or state. > > > > > > > > Yes for some it may be very useful feature and I am sure some will > call it overload of data plane or . There is no one size fits all. > > > > > > > > With that let's observe that till today SR did not require any new > mapping plane to be distributed in control plane and to be inserted into > data plane. This is clearly a precedent. > > > > > > > > Furthermore as we see in companion documents all additional network > functionality is being taken away from SRH and is being shifted to > Destination Options . > > > > > > > > As far as mapping plane I already pointed out in my Vector Routing > proposal that we have one already it is called BGP. One needs to also > observe that we as industry worked number of years of protocol suite called > LISP allowing not only very good mapping plane, but also data plane > integration. CC-ing lisp authors for their comments. Note also work for > integrating SRv6 with LISP which is already is published. > > > > > > > > Since you correctly observed that now SID can be 32 bit and that is > similar to the size of IPv4 my fundamental question is why not use > something which already exists instead of defining some sort of new from > scratch ? > > > > > > > Robert, > > > > > > I don't see in the SRH draft where 32 bit SIDs are defined. Can you > > > please provide a reference? > > > > > > > To clarify, I've been thinking about the idea of a smaller SID size > > for IPv6 for a while now (since inserting EHs came up), and thought > > about what would be a generic single size that might suit SR that > > wasn't the same size as an IPv6 address. 32 bits seemed suitable to > > me, although if people wanted bigger, I'd be suggesting 64 bits (not > > entirely coincidentally the common IID size.) > > > > Ron and others have written this draft, which supports SIDS of various > > sizes - 8, 16 or 32 bits - that triggered this discussion. > > > Mark, > > Why not just put a SID length field in the header (like RFC6554 but > more generic). That would allow lengths of 1-16 bytes. Additional > flags could be used to indicate the semantics of the entries. For > instance, they might be actual addresses (128 bits for IPv6, 32 bits > for IPv4), parts of addresses (prefixes of suffixes like in RFC6554) > where the rest of the address can be inferred, indices into a table, > labels, etc. > > Tom > > > "The IPv6 Compressed Routing Header (CRH)" > > https://tools.ietf.org/html/draft-bonica-6man-comp-rtg-hdr-03 > <https://urldefense.proofpoint.com/v2/url?u=https-3A__tools..ietf.org_html_draft-2Dbonica-2D6man-2Dcomp-2Drtg-2Dhdr-2D03&d=DwMFaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF2EfpHcAwrDThKP8&m=GjqK8FoNrV07C15WLojvSxgX5EiIQWc_RaJ_gD9iJAI&s=Btt5PY_Iq3PKjxOHh5GSUQWMX0kPIYqZokMCtz2JA28&e=> > > > > Regards, > > Mark. > > > > > > > As for trying to use something that already exists, why does SR used a > > > fixed size format for SIDs instead of a variable length format like > > > that described in RFC6554? Similarly, why does SR define it's own TLV > > > format instead of using Hop-by-Hop and Destination Options defined in > > > RFC8200? > > > > > > Tom > > > > > > > It will be perfectly fine to have full proper SRv6 with SRH and LISP > or Vector Routing as an alternative options. I really do not see a room or > need for yet one more mapping plane. What problem does it solve which would > not be already solved elsewhere ? > > > > > > > > Kind regards, > > > > Robert > > > > > > > > > > > >>> 2) Is there an agreement that solutions which require additional > per SR path state in both control plane and now in data plane are really > something we should be endorsing here ? > > > >> > > > >> > > > >> I think so. > > > >> > > > >> My understanding of what SR is fundamentally about is to reduce > control plane state and processing. The trade-off for reduced control plane > state and processing is to instead carry and encode most or all of that > information or its semantics as per-packet overhead. > > > >> > > > >> If the per-packet overhead becomes too large and expensive, then > pushing some of that information and processing back into the control plane > should be ok, as long as there is still a beneficial overall reduction in > control plane state and processing. > > > >> > > > >> As MPLS SR SIDs are 20 bits, then rounding up to an octet boundary > and a 32 bit alignment, I'd think 32 bit SIDs would be adequate to perform > SR in an IPv6 network. > > > >> > > > >> As 32 bit SIDs are also the same size as IPv4 addresses, that may > also create some opportunities to leverage IPv4 support in existing > protocols to suite carrying and processing 32 bit SIDs with some, possibly > slight, modification. For example, perhaps IPv4 Address Family support in > OSPFv3 (RFC 5838) could be somehow leveraged to suit SR. > > > >> > > > >> Regards, > > > >> Mark. > > > > > > > > -------------------------------------------------------------------- > > > > IETF IPv6 working group mailing list > > > > ipv6@ietf....org <ipv6@ietf.org> > > > > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_mailman_listinfo_ipv6&d=DwMFaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF2EfpHcAwrDThKP8&m=GjqK8FoNrV07C15WLojvSxgX5EiIQWc_RaJ_gD9iJAI&s=ozK7wzssqc1x3UQrEGZppBNd64FlYwd3RvhzdvZu5Uw&e=> > > > > -------------------------------------------------------------------- > > -------------------------------------------------------------------- > IETF IPv6 working group mailing list > ipv6@ietf.org > Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 > <https://urldefense.proofpoint.com/v2/url?u=https-3A__www.ietf.org_mailman_listinfo_ipv6&d=DwMFaQ&c=HAkYuh63rsuhr6Scbfh0UjBXeMK-ndb3voDTXcWzoCI&r=Fch9FQ82sir-BoLx84hKuKwl-AWF2EfpHcAwrDThKP8&m=7oInX5oGRmd36ozKW9gDLBfD4hBl0G89as-W-cNq90s&s=DgsqbOLgIMGesxMPjVyRODst-R9NG4CWqnD02hIVOXc&e=> > -------------------------------------------------------------------- > >
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Dino Farinacci
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Mark Smith
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Dino Farinacci
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Tom Herbert
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Ron Bonica
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Dino Farinacci
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Mark Smith
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Tom Herbert
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Mark Smith
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Ron Bonica
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Gyan Mishra
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Tom Herbert
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Ron Bonica
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Ron Bonica
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Tom Herbert
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… James N Guichard
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Dino Farinacci
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Ron Bonica
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Robert Raszuk
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Greg Mirsky
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Gyan Mishra
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Tom Herbert
- Re: [lisp] [spring] IPv6-compressed-routing-heade… Greg Mirsky