From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2B977C5519F for ; Thu, 12 Nov 2020 16:13:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2ECF22227 for ; Thu, 12 Nov 2020 16:13:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=networkplumber-org.20150623.gappssmtp.com header.i=@networkplumber-org.20150623.gappssmtp.com header.b="CdOmQcKr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728707AbgKLQNK (ORCPT ); Thu, 12 Nov 2020 11:13:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728233AbgKLQNK (ORCPT ); Thu, 12 Nov 2020 11:13:10 -0500 Received: from mail-pf1-x429.google.com (mail-pf1-x429.google.com [IPv6:2607:f8b0:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C238C0613D1 for ; Thu, 12 Nov 2020 08:13:10 -0800 (PST) Received: by mail-pf1-x429.google.com with SMTP id a18so4967369pfl.3 for ; Thu, 12 Nov 2020 08:13:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=92txTY+sQLiIPy5s8ibLbhDy+/gFwXaDoJ2fu1Ityis=; b=CdOmQcKrGimqjFIFOSbux3oD12SM4ZOrOVn5jxddtC7rI1WMsCZogWV2AZw3OZWEAc HO3cFAUfRK6dnEWbp1wFczz1ugAG7J/NTCsNLf1Wblneyyo1h4NRBOWag+nHFFkE3LRo qCV2Nnqm6zi2o52xLC37zUfdg1t1RaOcUAQSXCEMNaEk/azz13EJyAcdDyiil84jGgHm ToPiMRPUd7MuMqkCxXnM4b4cIlRDY3sGfvCh/nqmEoXYd0KBJFNSO1Rgp8wx7/NKDQZe agK7DrVhNBlbjraZV2QLsTUGaJXZOK4Y6hefSd9VCz1M8u8C77VjlIXqpLSrU59sQ3L6 u9Mw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=92txTY+sQLiIPy5s8ibLbhDy+/gFwXaDoJ2fu1Ityis=; b=J1LrW525aH92/ikzBlVHKNAThekXMk/k+8gH2EF7hV/rhM8/nPyiSrYknl5oOVgCYc 7y+GD/9FMJZ/SAnC2RsriYvQvZfkV+xG5R+g+TgdW6fRssPgM/G01HBItYmmZt62Gr5O SbxA2XeMgO7gi8c65U4i9aBHwa+WqfBjoM/xq7YYDTEPeoAC2LPMRwrtRAVHSxvY/B7M FrvfpBaNvyHrn8hxOGeazAc+F1uZJobzLT3moO2qESMCqa5oe+ZvsbiZMmMY7GjbjSKL mhXUMcImTjkxMsqfUxeSLIPY0lDk5k6k2lp0l0aLwYBxFlHAU7rRYKqumHmelCo1jP01 Ccug== X-Gm-Message-State: AOAM531VqPkfyR1Rg0pWakzEgPEmF3Tn/NmI5+lqPvjYVQ9eEbeChfA/ S6ondJl/rU313akOA8ptGuvnIe4w2smqjrzD X-Google-Smtp-Source: ABdhPJzbTBdn0+XYeQ9hN/mbMMrfeN01uDShjF8afZKJxV2ezJdNdUh0ncyyTYSct6HeE4s0/TWDLw== X-Received: by 2002:a17:90a:5b15:: with SMTP id o21mr9935496pji.45.1605197590042; Thu, 12 Nov 2020 08:13:10 -0800 (PST) Received: from hermes.local (204-195-22-127.wavecable.com. [204.195.22.127]) by smtp.gmail.com with ESMTPSA id b21sm3990027pjo.43.2020.11.12.08.13.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Nov 2020 08:13:09 -0800 (PST) Date: Thu, 12 Nov 2020 08:13:06 -0800 From: Stephen Hemminger To: Russell Strong Cc: netdev@vger.kernel.org Subject: Re: IPv4 TOS vs DSCP Message-ID: <20201112081306.0496a95b@hermes.local> In-Reply-To: <20201112100954.62d696b6@192-168-1-16.tpgi.com.au> References: <20201112100954.62d696b6@192-168-1-16.tpgi.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 12 Nov 2020 10:09:54 +1000 Russell Strong wrote: > Hello, > > After needing to do policy based routing based on DSCP, I discovered > that IPv4 does not support this. It does support TOS, but this has > never been upgraded to the new ( now quite old ) DSCP interpretation. > > Is there a historical reason why the interpretation has not changed? > > I could copy the dscp into a fwmark and then use that, but that seems a > little unnecessarily complicated. If I were to change this, what would > be the objections? > > Russell Probably a couple of reasons: no one needed it badly enough to work on it. And more importantly any change would have to retain the legacy behavior as the default.