[Sidrops] An alternative approach to draft-ietf-grow-route-leak-detection-mitigation

Iljitsch van Beijnum <iljitsch@muada.com> Tue, 02 July 2019 10:22 UTC

Return-Path: <iljitsch@muada.com>
X-Original-To: sidrops@ietfa.amsl.com
Delivered-To: sidrops@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 33566120052; Tue, 2 Jul 2019 03:22:31 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -2.701
X-Spam-Level:
X-Spam-Status: No, score=-2.701 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_PASS=-0.001] autolearn=ham autolearn_force=no
Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=muada.com header.b=fkxDuodX; dkim=pass (2048-bit key) header.d=messagingengine.com header.b=V/AdIiIq
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 T19zeOAiNc_t; Tue, 2 Jul 2019 03:22:29 -0700 (PDT)
Received: from wout4-smtp.messagingengine.com (wout4-smtp.messagingengine.com [64.147.123.20]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 447B5120044; Tue, 2 Jul 2019 03:22:29 -0700 (PDT)
Received: from compute2.internal (compute2.nyi.internal [10.202.2.42]) by mailout.west.internal (Postfix) with ESMTP id 6620A471; Tue, 2 Jul 2019 06:22:28 -0400 (EDT)
Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Tue, 02 Jul 2019 06:22:28 -0400
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=muada.com; h= content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; s=fm3; bh=X g4+df9HQmKBe+QApMV3Qz+CBVG1GAh9XOgqQKEfjVs=; b=fkxDuodXRsxqBk3x9 qb4Bx6FnWcn6E+uznMAOPjssNgtTq/KJQEFSG5RhxZMV3kUA7JcXf2RGHsJ7GxSb ayK4NnZJ11gC/IgEMnskH17przx5uI1MV39ncFiW1XNsK8kF8whrzwu8IoqamdUf 4dkEhpDloUfvWf9rUxh6NbowxZhWBJ+Sp2RLr8pEYKTOov04IgrGbQOuoOPoCWQL ykdC+iKhNfpyLAYNLyUMRqtOiPPaEIZYlAcJEmgMuyLeuD/MEWKOq3DSV50A10Ew usfMBtYCdzPM+v4+i//i3sgtkoSu+XGfYK4g+TUL8KzH9FjpzH8y04rVO3J08lGK S5iQg==
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:in-reply-to:message-id:mime-version:references :subject:to:x-me-proxy:x-me-proxy:x-me-sender:x-me-sender :x-sasl-enc; s=fm3; bh=Xg4+df9HQmKBe+QApMV3Qz+CBVG1GAh9XOgqQKEfj Vs=; b=V/AdIiIqjitC2PYDEKArjQ+PDTUBwOshF70nbDGIsURDsulbQxIfRTIPT DOtAjkiY54x1SVRmmuFIyhKIYhEXnalTRoT+v5E8QIi2kGzHt7aU44OlsgFT7/+V FwqGIr/5teVOJR8u0RSTg6BtDj1BahLk2g5im/iIMHwOeOTYcSPXJuo5LnXu96HW UX08Hu0SNT9sDPGmCEUeSrXWEzpSNuP3P8t+iwnPGQS+rcy4oMLD+LH6e8F8atan 1W5YincXdvxIU3ZqVzFnIpwBadzLYCYmyw6j1FTzuiPhCKugKeQfPXgUiwr1NknA mJoh18AZw0Q1/CbRmhR4y2E+IvHIw==
X-ME-Sender: <xms:YzAbXTB4ClWdCFN7f_8rl7xfBPujhTzKwUldACdmytxrQQoqvKA-DA>
X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduvddrvdekgddvlecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecunecujfgurheptggguffhjgffgffkfhfvofesthhqmh dthhdtvdenucfhrhhomhepkfhljhhithhstghhuchvrghnuceuvghijhhnuhhmuceoihhl jhhithhstghhsehmuhgruggrrdgtohhmqeenucfkphepkeefrdekhedrjedurdelheenuc frrghrrghmpehmrghilhhfrhhomhepihhljhhithhstghhsehmuhgruggrrdgtohhmnecu vehluhhsthgvrhfuihiivgeptd
X-ME-Proxy: <xmx:YzAbXf2Pbt7VuazoVAVPZqMCNg8qQFJ6w0YiXXcbKR2SgFFICELBtw> <xmx:YzAbXbTz5ENN2tDW6ZwzuzsTMejATv8vBLRvZPNk1ihg5tQb3EKQKw> <xmx:YzAbXUb0FlWex5GlsjGRIafQ_zOrUUVhB_cJp72ZMvvzFN5qLlqz6A> <xmx:ZDAbXass21caxtl6CJXNqk9BkavntrcvbVCtt1xttAjBeta0CYtXUg>
Received: from [192.168.178.17] (83-85-71-95.cable.dynamic.v4.ziggo.nl [83.85.71.95]) by mail.messagingengine.com (Postfix) with ESMTPA id 365FE80065; Tue, 2 Jul 2019 06:22:27 -0400 (EDT)
Content-Type: text/plain; charset="us-ascii"
Mime-Version: 1.0 (Mac OS X Mail 12.4 \(3445.104.8\))
From: Iljitsch van Beijnum <iljitsch@muada.com>
In-Reply-To: <CAEGSd=CMhjpFramk_oNjO9g2YTmXvvntrjwBjXtc8D=EUTpBbw@mail.gmail.com>
Date: Tue, 02 Jul 2019 12:22:24 +0200
Cc: sidrops@ietf.org
Content-Transfer-Encoding: quoted-printable
Message-Id: <465695D1-51CD-49A6-9126-A7125E12062F@muada.com>
References: <20190528162707.GD29921@hanna.meerval.net> <CAH1iCip6YmGri9Eq5YvHqs8bqooNMYcY_fPYGQ4v5epcc9oV_w@mail.gmail.com> <b8d27bb4-32a1-281e-7361-a58da8a28dc7@foobar.org> <CAEGSd=CMhjpFramk_oNjO9g2YTmXvvntrjwBjXtc8D=EUTpBbw@mail.gmail.com>
To: grow@ietf.org
X-Mailer: Apple Mail (2.3445.104.8)
Archived-At: <https://mailarchive.ietf.org/arch/msg/sidrops/RDhlNSPXHotkTXfUs4thD7iWo94>
Subject: [Sidrops] An alternative approach to draft-ietf-grow-route-leak-detection-mitigation
X-BeenThere: sidrops@ietf.org
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: A list for the SIDR Operations WG <sidrops.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/sidrops>, <mailto:sidrops-request@ietf.org?subject=unsubscribe>
List-Archive: <https://mailarchive.ietf.org/arch/browse/sidrops/>
List-Post: <mailto:sidrops@ietf.org>
List-Help: <mailto:sidrops-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sidrops>, <mailto:sidrops-request@ietf.org?subject=subscribe>
X-List-Received-Date: Tue, 02 Jul 2019 10:22:32 -0000

Hi all,

I was made aware of this draft in sidrops, and wrote there that I don't think it'll work because the AS in DO is overwritten with _last_ AS that propagates a route over peering rather than the _first_ (origin) AS. Maybe with the L thing everything will still work, but now that I see here that the point is to make it work using existing mechanisms, I don't see how that can happen. The community filters and route maps to make it all work would be way too complex.

Also, if you _really_ want to deploy tomorrow, don't use large communities or extended communities, because those aren't implemented widely enough: use regular communities.

But it all comes back to this: if you see a DO, how do you know it's one from multiple hops away that indicates a leak, rather than one from the neighboring AS that is not problematic?

My conclusion: this can't work and be deployed realistically with any type of communities.

But you know where you can stick information that will be linked to a specific place in the AS path?

In the AS path.

What if we prepend all prefixes we announce to a peer with a 1, and prepend all prefixes that we receive from a peer wit a 2.

So if there's a 1 or a 2 more than one hop beyond our peer AS, we have a leak.

Adding a provider - customer indicator is left as an exercise for the reader.

The only downside that I see is that with partial deployment, certain paths will be longer while others remain the same length for now, which will have impact on traffic engineering.

Iljitsch