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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_2 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 3FAB8C56201 for ; Thu, 12 Nov 2020 01:50:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB59720791 for ; Thu, 12 Nov 2020 01:50:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728136AbgKLBcU (ORCPT ); Wed, 11 Nov 2020 20:32:20 -0500 Received: from smtp.netregistry.net ([202.124.241.204]:59756 "EHLO smtp.netregistry.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728035AbgKLAP0 (ORCPT ); Wed, 11 Nov 2020 19:15:26 -0500 X-Greylist: delayed 322 seconds by postgrey-1.27 at vger.kernel.org; Wed, 11 Nov 2020 19:15:26 EST Received: from 124-148-94-203.tpgi.com.au ([124.148.94.203]:32948 helo=192-168-1-16.tpgi.com.au) by smtp-1.servers.netregistry.net protocol: esmtpa (Exim 4.84_2 #1 (Debian)) id 1kd0BZ-0002jp-N1 for ; Thu, 12 Nov 2020 11:10:00 +1100 Date: Thu, 12 Nov 2020 10:09:54 +1000 From: Russell Strong To: netdev@vger.kernel.org Subject: IPv4 TOS vs DSCP Message-ID: <20201112100954.62d696b6@192-168-1-16.tpgi.com.au> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.32; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Authenticated-User: russell@strong.id.au Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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