Re: [bess] handling DAD in draft-ietf-bess-evpn-inter-subnet-forwarding-05

Sowmini Varadhan <> Thu, 31 January 2019 09:39 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 5AEE9128D09 for <>; Thu, 31 Jan 2019 01:39:46 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -1.75
X-Spam-Status: No, score=-1.75 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_PASS=-0.001] autolearn=no autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id eT5wR50f5_gE for <>; Thu, 31 Jan 2019 01:39:45 -0800 (PST)
Received: from ( [IPv6:2607:f8b0:4864:20::334]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id 39CC5126CB6 for <>; Thu, 31 Jan 2019 01:39:45 -0800 (PST)
Received: by with SMTP id u16so2239079otk.8 for <>; Thu, 31 Jan 2019 01:39:45 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=QV6saIMv1ua9EYZ9BdlQM1oqBiGQs4hrj7SS/hnxWvk=; b=lNJib1SYuWlb1p/4Lwe6tJ5l/U71Y+9tCmjuTEjJCPHMEt3vT18qAa+lyAoR1tyvYH nATVw3RY8BR3r2JzPQc+mfJRiOVyQaaaThi66VLCjVxC5us5G3yV3/rqS+rHiEdUhbyt vv+PUoAQ7rJY3IChZ/zWVtIQ8nXwwug7qUJy4WKrG6DeQoEPdM6xwF537ytBA1e+XCOh 9fEYJzRA9y7stf6Coh/H73XkqoUabaIjdGbTAZgOOKkKWC1UUHyzeNEK1s/+TbYSeXrs L+V7sCsZzxZESO6Vtyb+J8hwi9oQkI06HBHE9eVtkbAKbodVXiZb07h+8Oao/JVGFzTL GnWg==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=QV6saIMv1ua9EYZ9BdlQM1oqBiGQs4hrj7SS/hnxWvk=; b=NHL1f17PeUACKfhCiSsv5i4K4/ngNxcVPAZHnRUmPbp5TjHuIv3xeh4oCxFF5Tl4i2 OH4wf7lgSZdQ+3PpHU2srhnSLYyRcpcazJqJXfnDBEqgpkDoxyLoIEkpvAtPUuTntItF yXJBLE3k14VjwVQ5MIFkw0JwxlYSut4NoH4UvVip05QxTlDZBT6CjKQqFh4YwoygTmuO nRtn4Pih1VP+33RUDsBExq0bnvACgqMr/VYiMAzmxL6pQuYgDhJJCQKZWVia+ZKn4dBi T0TqJOEgLIumFR7dma7gTHloZD4KkLz1DxheIEttOuaaBymw3LZTpBYkV67xT9eXEbdE K+Lg==
X-Gm-Message-State: AJcUukdMORRBAWF+sI0yZK4TcFE40NPURINkzpONmuozKMkRVi8tJc44 ONABSw92PooCIz+kgN3kQOkJDDWwwBtlksjlDrc=
X-Google-Smtp-Source: ALg8bN5M4xrlWT4J/+tuYPpB2EX0tl0uKHITobVIghfZUg3TVOiffdhdsbgXVGPOHXMvwrpoVle3nFnv5Y5Qg/bHCCU=
X-Received: by 2002:a9d:6f09:: with SMTP id n9mr23858544otq.87.1548927584590; Thu, 31 Jan 2019 01:39:44 -0800 (PST)
MIME-Version: 1.0
References: <> <>
In-Reply-To: <>
From: Sowmini Varadhan <>
Date: Thu, 31 Jan 2019 04:39:32 -0500
Message-ID: <>
To: "Ali Sajassi (sajassi)" <>
Cc: "" <>, John E Drake <>, "Samir Thoria (sthoria)" <>, Sowmini Varadhan <>, "" <>, "sslam(mailer list)" <>
Content-Type: text/plain; charset="UTF-8"
Archived-At: <>
Subject: Re: [bess] handling DAD in draft-ietf-bess-evpn-inter-subnet-forwarding-05
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: BGP-Enabled ServiceS working group discussion list <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Thu, 31 Jan 2019 09:39:46 -0000

On Wed, Jan 30, 2019 at 9:20 PM Ali Sajassi (sajassi) wrote:

sajassi> AS> RFC 7431 has procedures for duplicate MAC address detection.

rfc 7431 is the Informational RFC titled "Multicast-Only Fast Reroute".

Perhaps you mean rfc 7432. And I suspect you mean Section 15.1

draft*evpn-inter-subnet-forwarding should call out this cross-reference
explicitly, so that the reader does not have to speculate (as I
just did)

sajassi> AS> If ARP probing is done before the target NVE gets to
declare that the TS has moved, then the MAC move is delayed
unnecessarily for ALL the legitimate MAC move cases which in turn can
cause some loss of traffic and degradation in service. It should be
noted that the MAC move procedures in here is consistent with RFC
sajassi> AS> same reply as above.

it's a bit odd that lot of chaos can happen for approx 3 mins
when there is actually a duplicate address (created accidentally
or maliciously) but I suppose you could say that this is already
based on 7431, so not something introduced by