Re: [Idr] TCP & BGP: Some don't send terminate BGP when holdtimer expired, because TCP recv window is 0

Robert Raszuk <> Sat, 12 December 2020 09:23 UTC

Return-Path: <>
Received: from localhost (localhost []) by (Postfix) with ESMTP id 0835F3A0EC6 for <>; Sat, 12 Dec 2020 01:23:07 -0800 (PST)
X-Virus-Scanned: amavisd-new at
X-Spam-Flag: NO
X-Spam-Score: -2.098
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, HTML_MESSAGE=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001] autolearn=ham autolearn_force=no
Authentication-Results: (amavisd-new); dkim=pass (2048-bit key)
Received: from ([]) by localhost ( []) (amavisd-new, port 10024) with ESMTP id fK9ds1Xtj8zW for <>; Sat, 12 Dec 2020 01:23:05 -0800 (PST)
Received: from ( [IPv6:2a00:1450:4864:20::134]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by (Postfix) with ESMTPS id A40AB3A0EC4 for <>; Sat, 12 Dec 2020 01:23:04 -0800 (PST)
Received: by with SMTP id m12so17659338lfo.7 for <>; Sat, 12 Dec 2020 01:23:04 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=OIHxB0Sa/I+RoSHvtessXX2dzxjf3+K7sjOOPIDiHZA=; b=KbwUA5FOJwEoc0t4FgntLxFN6A5qK8hKyMUSww4Az+0Z9AUDFNaAAxqZ6TjZ65Nlir L2usI4OuAKiJLYan2u4UImmN/dHlJO6U/R0l+EUECmCd1NwCLa8RcmrQfA15bPBwnQhk PlJADGONlLXQdFPGo0BQ3izhOlxsWNLVdtRqhEqqENX11/vLz0AXDxZHNtm9ZvrBqdtE 19UIj5lTy4NR15Y9/C5h1t1ZYd7grW8bNdck1ZJc3Bi7gN91aVdB9zd5nX8qzJjVVulw oPjgqdwBpny2syEy7ZV2RJu/hFnPCcbzlIApLJddsdkqBDykXnGhDW8yJ8ONRQQkhQUt edxw==
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=OIHxB0Sa/I+RoSHvtessXX2dzxjf3+K7sjOOPIDiHZA=; b=Z4x8EP9u5X+OZgNDVcJVougk3nRQcMPvpmJwi84f2oDie1eoOVFjEaPLKmmB9wDwgj DBJZxE/xfgHHtwk71Rhekqw26RDavpN9F/8Q4LJqPs7w/etRkveV8oEtrWARirG5H8bv fpZlkGKPgWj8TJVHRb3rKXeQZxf6qSY401msj1lLmPOW+8ze0N1YMSPNzJfRLHKaRxH4 wAPHW7XIfAWI5t9ujRdRcqF8tW1+tH4xmO8g75KWHx54JSsXQYzXFcuWX/X8jMZtjDP/ sDfJ3dUy1rbTdrzAg/6Ls7DayjhSyAUUv6Dcv6BD/U5WjVkKQk9YrURWIo2zG2+3uyLT dCOw==
X-Gm-Message-State: AOAM531Bof/FhSxu9/spS6tce+pYQwxhz9cPS7O/omTqY8/9iOSEXyls 3Hk1wUHKCoBxc5L6f3YD3NgVRZQ/2W21ujv8iZeGSLb65/E7qQ==
X-Google-Smtp-Source: ABdhPJwiGbyckmCL79WjpWO06UwbElGcT+8ph5+Y5N+mTYj8HBTmlbBKXj+reivnFkcE5vXlpqeSk4OCAKRnZngvTV0=
X-Received: by 2002:a2e:9dd4:: with SMTP id x20mr3889335ljj.37.1607764982610; Sat, 12 Dec 2020 01:23:02 -0800 (PST)
MIME-Version: 1.0
References: <>
In-Reply-To: <>
From: Robert Raszuk <>
Date: Sat, 12 Dec 2020 10:22:53 +0100
Message-ID: <>
To: Job Snijders <>
Cc: "idr@ietf. org" <>
Content-Type: multipart/alternative; boundary="000000000000abd01205b640f44a"
Archived-At: <>
Subject: Re: [Idr] TCP & BGP: Some don't send terminate BGP when holdtimer expired, because TCP recv window is 0
X-Mailman-Version: 2.1.29
Precedence: list
List-Id: Inter-Domain Routing <>
List-Unsubscribe: <>, <>
List-Archive: <>
List-Post: <>
List-Help: <>
List-Subscribe: <>, <>
X-List-Received-Date: Sat, 12 Dec 2020 09:23:07 -0000

I went back and reread the thread:

Shouldn't it be better if we first ask implementations to provide show
command/api to list all peers and min-max durations of TCP Window being 0
without actually doing any automagic RST/NOTIFICATION/FIN ?

This could allow to better understand which peers are getting behind in
their control plane and perhaps also allow to set the RST timer under such
conditions by operator? If he chooses this to be equal to HOLD TIME so be
it but I am not sure this would be universally an optimal choice.

Along the same lines we should perhaps also list per BGP peer number of

Are there implementations already deployed in DFZ allowing such data to be
displayed per each BGP peer ?