From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 19726 invoked from network); 7 May 2022 16:23:14 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 7 May 2022 16:23:14 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 650CC9D436; Sun, 8 May 2022 02:23:12 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 8D2139CEF1; Sun, 8 May 2022 02:20:34 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="KoLqF3AU"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 5E9089CEEF; Sun, 8 May 2022 02:14:16 +1000 (AEST) Received: from mail-lj1-f182.google.com (mail-lj1-f182.google.com [209.85.208.182]) by minnie.tuhs.org (Postfix) with ESMTPS id 945B19CEEE for ; Sun, 8 May 2022 02:14:15 +1000 (AEST) Received: by mail-lj1-f182.google.com with SMTP id y19so12426675ljd.4 for ; Sat, 07 May 2022 09:14:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:from:date:message-id:subject:to; bh=o1u/6jIRBts8t9sq1sMo/iOkG89k0r1O/0TtHWHIEsg=; b=KoLqF3AUcr6vqKyqxb/X9K2udpVzX+zEoeKOgkl6wYen4fTA1oK231N2mBic05/ACr ObPVxLGAeSOkmj6t3oIXuUeNz4PYnPP3rAGx06ABf0STShAfpe2j0VG8/YklgMiDVU8q t71Jo17XOIjTCMorA6x7KwRYzJ8s7YhhF1u9z2aoW6Ev3I1o/K3cbDZEuhF0DRi5H9MO eYOKrXImKrhvJhhThYWU25TK24LIkvcmRMFBcagzAPZ50K/e9kXB5kD4MDPzWYfN29/d Wi8HyGmdW7k/OfIxnVUibkw1IGd5qMp5GVqJTK2NdodV1BrDSLcDUQ7YOVUSA7MHYoB0 HPcg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:from:date:message-id:subject:to; bh=o1u/6jIRBts8t9sq1sMo/iOkG89k0r1O/0TtHWHIEsg=; b=aIo2fc4WASE5TqNXpC2WIzkSCAHTSEUaQ5WeruPXkN+1b1VxCvijQVqOEIj1N4p6oJ LADGzJhxOlni4A/6Od+Y/5MPGU8q3RvPCsampFdE7S7Y6n/XbEEs9cNoVYQQaF+MNhWi e7dzAPeqvLvrXk1sjA3qdkk0qWuxqDmRm9g2Zh28WlqAmW1GfRgBPoW4FrQg5bupqxxt WagZjHIpaJq9bFY2JeHv+ijpsm7B//42wwjzt9li0dPiL4tW3hrauMm7eHKEvuNptmOA l3tjh73PlbdwvxOutH8o6LvpS7z+hQe6B94AxzJI5sb0pmjtHxn5SFQXh/i+lgMSlBIM luhg== X-Gm-Message-State: AOAM5324L9N7w5mBItdqWg8NMNnkanU7BdCOhNlrJLQzNc2RQHRfMMn4 xtwStM2wmPRUuMZVMvJZXJUwG9qdtIeUNAoMxeFFxfuQkRY= X-Google-Smtp-Source: ABdhPJxvHTNP8rZ324PSNxFHwZo5fEyI9EzeUVv6/qXqP+Zcg3txYD3zsFoW5geTTEalWlWpDBQaqDXBsB8TX2WLaLE= X-Received: by 2002:a2e:b047:0:b0:250:a20e:2b4 with SMTP id d7-20020a2eb047000000b00250a20e02b4mr4822449ljl.184.1651940053444; Sat, 07 May 2022 09:14:13 -0700 (PDT) MIME-Version: 1.0 From: ron minnich Date: Sat, 7 May 2022 09:14:01 -0700 Message-ID: To: TUHS main list Content-Type: text/plain; charset="UTF-8" Subject: [TUHS] conventions around zero padding in ip4 X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" I first learned in the 80s that 127.1 meant 127.0.0.1. I always assumed zero padding was defined in a standard *somewhere*, but am finding out maybe not. I talked to the IP OG, and he tells me that padding was not in any standard. [side note: it's weird and wonderful to still have so many people "present at the creation" of computing as we know it still around, and to find they are so willing to answer naive questions!] Padding is a standard in ip6, possibly because the addresses are so long. :: is your friend. IP4 padding came up recently: the ip command interprets 10.2 as 10.2.0.0, whereas most things (golang libraries, ping, ...) interpret it as 10.0.0.2. The latter interpretation accords with what I learned 40y ago. But, I find myself wondering: where was the first use of the IP4 zero padding convention?