Re: [dhcwg] [EXTERNAL] [v6ops] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-requirements

Bob Hinden <bob.hinden@gmail.com> Wed, 14 October 2020 21:46 UTC

Return-Path: <bob.hinden@gmail.com>
X-Original-To: dhcwg@ietfa.amsl.com
Delivered-To: dhcwg@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id D963D3A10BE; Wed, 14 Oct 2020 14:46:53 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.098
X-Spam-Level:
X-Spam-Status: No, score=-2.098 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com
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 BzvFAtas-RzC; Wed, 14 Oct 2020 14:46:52 -0700 (PDT)
Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) (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 B55DC3A08E3; Wed, 14 Oct 2020 14:46:51 -0700 (PDT)
Received: by mail-wr1-x435.google.com with SMTP id x7so779454wrl.3; Wed, 14 Oct 2020 14:46:51 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:message-id:mime-version:subject:date:in-reply-to:cc:to :references; bh=5r3fI9lgf5nTX/6lvotxuGoSg02mwOUALuZaMvOGSLw=; b=qce8WLd2MRMJBn0xuBHtnkEo2cohd4+nRYXhny+fYE1JqELdATf1ykwrPCyKFAYtwp Jvkf3TMFs4ZpAuk1U5tTqBwFLRr5tc5Abbw8yQONaD+CYfKqaLYs0ZhbXUikLYZbUrIM GcTRi0G0DSAdTsM3oZevYn5yKEhNBaN5uYiqa78obVofHDimE5an03uV690WuYBm66Mz TXNZkFxIJGLeldWmzuPjq8IKtz8bP2iXMkj/eF0N4JRyKGVJls3ewSogzBlEEw4As3O1 cWsJSCPEKetwYwwjBYbE+WuqyV27FJDWY7g7lTMWsZ43/wmDHa7GUp/SGU7RBejE7Uol b8ZQ==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:message-id:mime-version:subject:date :in-reply-to:cc:to:references; bh=5r3fI9lgf5nTX/6lvotxuGoSg02mwOUALuZaMvOGSLw=; b=bu+mkDSP8Es+WVqRC2Fd1/6fr6ILX7TuOkx8G/OwqwmTxQlQgxWID/0KwSVtUYmkzD +2nwPSxVCPjYuyf95KOa5EDcwteAppmf+QGj64KeMatwQnWQbwGHDYZDrhP/vc/sRwN5 jeSRo4ItTLyWLkn0aWwoYLsi9sFXsBlOUpNtGPuEmdfmIqmNfP8x6hAdFcv1q/j9b3Xt c9ocWfSfHEYlPDNBTH7vY0THXc8TqCnD7/ycbkHAX5rvYbjkXaStFwUuoZVi8R3EL8Ln 6RpbNQ4aYpn4NXkdnPXMrWqyJtuPtyIIWi3SlrQ9M5MF+ggaoSLpPSyzPZ3cCLZVh2pp V30w==
X-Gm-Message-State: AOAM532L7kIRMeveg7POM3G2+HBBB4d2ay93C+wwEWLySSBcLD+2CIl0 RHDmgy2pZD4bZLzTD7E4glE=
X-Google-Smtp-Source: ABdhPJyOhg6cuTN1+V+nqHrj+ob9aTMv6k7GWjgN5lc5H+uOm7Z0hy44/EnWZrb5rtJSWCd/1hrbYA==
X-Received: by 2002:adf:bbd2:: with SMTP id z18mr833362wrg.166.1602712010119; Wed, 14 Oct 2020 14:46:50 -0700 (PDT)
Received: from [10.0.0.199] (c-24-5-53-184.hsd1.ca.comcast.net. [24.5.53.184]) by smtp.gmail.com with ESMTPSA id t19sm1190427wmi.26.2020.10.14.14.46.48 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 14 Oct 2020 14:46:49 -0700 (PDT)
From: Bob Hinden <bob.hinden@gmail.com>
Message-Id: <BD2B4938-B362-40A7-BCF7-DDA270A64BF7@gmail.com>
Content-Type: multipart/signed; boundary="Apple-Mail=_5DE75560-C61D-40CA-8C13-DC6ED2424C76"; protocol="application/pgp-signature"; micalg=pgp-sha512
Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.17\))
Date: Wed, 14 Oct 2020 14:46:44 -0700
In-Reply-To: <1b34b9bec59e4a00af8b9d8f182d23ff@boeing.com>
Cc: Bob Hinden <bob.hinden@gmail.com>, Michael Richardson <mcr+ietf@sandelman.ca>, dhcwg <dhcwg@ietf.org>, IPv6 List <ipv6@ietf.org>, v6ops list <v6ops@ietf.org>
To: "Templin (US), Fred L" <Fred.L.Templin@boeing.com>
References: <5f119ffbb67245a9b9d34a0d8f7398f4@boeing.com> <10487.1602608586@localhost> <378d3420690246bbae253fb15be8c9a7@boeing.com> <19627.1602701863@localhost> <1b34b9bec59e4a00af8b9d8f182d23ff@boeing.com>
X-Mailer: Apple Mail (2.3445.104.17)
Archived-At: <https://mailarchive.ietf.org/arch/msg/dhcwg/7AaGN-OqMgHojeBLgtNVjSUfg-E>
Subject: Re: [dhcwg] [EXTERNAL] [v6ops] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-requirements
X-BeenThere: dhcwg@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: <dhcwg.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/dhcwg/>
List-Post: <mailto:dhcwg@ietf.org>
List-Help: <mailto:dhcwg-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/dhcwg>, <mailto:dhcwg-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 14 Oct 2020 21:46:54 -0000

With my chair hat on, is there a reason why this discussion is being copied to the 6MAN w.g.?   6MAN doesn’t maintain DHCP related items.

Please remove ipv6@ietf.org from this thread.

Bob


> On Oct 14, 2020, at 12:19 PM, Templin (US), Fred L <Fred.L.Templin@boeing.com> wrote:
> 
> Hi Michael,
> 
>> -----Original Message-----
>> From: Michael Richardson [mailto:mcr+ietf@sandelman.ca]
>> Sent: Wednesday, October 14, 2020 11:58 AM
>> To: Templin (US), Fred L <Fred.L.Templin@boeing.com>
>> Cc: ianfarrer@gmx.com; Jen Linkova <furry13@gmail.com>om>; dhcwg <dhcwg@ietf.org>rg>; v6ops list <v6ops@ietf.org>rg>; 6man
>> <ipv6@ietf.org>
>> Subject: Re: [EXTERNAL] Re: [dhcwg] [v6ops] Re: Question to DHCPv6 Relay Implementors regarding draft-ietf-dhc-dhcpv6-pd-relay-
>> requirements
>> 
>> 
>> Templin (US), Fred L <Fred.L.Templin@boeing.com> wrote:
>>> Michael, what I was referring to below as "failure" is the proxy case when
>>> there is an L2 proxy P between the client and relay (e.g.,
>>> RFC489). There
>> 
>> RFC4389 describes an ND Proxy.
>> Is that really an L2 proxy?
> 
> Yes, I believe it is an L2 proxy.
> 
>> It seems like it also must be contain either an L2-bridge, or must have the
>> L3-routing table entries if it would really be capable of passing DHCPv6-PD
>> prefixes through it.
> 
> The only thing it has that includes L3 information is neighbor cache entries that
> keep track of the client's actual L2 address on the downstream link segment,
> but rewrites the client's L2 address to its own L2 address when forwarding
> onto an upstream link segment. (In the reverse direction, it receives packets
> destined to its own L2 address but the client's L3 address on the upstream
> link segment, then rewrites the L2 address to the client's L2 address when
> forwarding onto the downstream link segment.)
> 
>> Can you explain how such a device would normally work for a client device
>> A,B,C,D doing DHCPv6-PD through it?
> 
> Sure. A sends a DHCPv6 Solicit using its IPv6 link-local address as the source,
> and its L2 address as the link-layer source. The proxy converts the link-layer
> source to its own L2 address when forwarding the DHCPv6 solicit onto the
> upstream link. When the DHCPv6 Reply comes back, the IPv6 destination is
> that of client A, but the link-layer destination is the L2 address of the proxy.
> The proxy then converts the L2 destination to the address of client A and
> forwards it on to the client.
> 
>> And is the failure one where the router "R" fails to drop traffic it should,
>> one where the router "R" drops traffic that it shouldn't?
> 
> I was thinking more along the lines of the latter; if the only way that A has
> for talking to B, C, D, etc. is by going through R, it wouldn't work if R was
> unconditionally dropping everything.
> 
> Thanks - Fred
> 
>> --
>> Michael Richardson <mcr+IETF@sandelman.ca>   . o O ( IPv6 IøT consulting )
>>           Sandelman Software Works Inc, Ottawa and Worldwide
>> 
>> 
>> 
> 
> --------------------------------------------------------------------
> IETF IPv6 working group mailing list
> ipv6@ietf.org
> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> --------------------------------------------------------------------