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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 821CEC04AAF for ; Thu, 16 May 2019 16:14:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4ECFE20815 for ; Thu, 16 May 2019 16:14:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZrvE9x9+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726954AbfEPQOf (ORCPT ); Thu, 16 May 2019 12:14:35 -0400 Received: from mail-pf1-f177.google.com ([209.85.210.177]:42447 "EHLO mail-pf1-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbfEPQOe (ORCPT ); Thu, 16 May 2019 12:14:34 -0400 Received: by mail-pf1-f177.google.com with SMTP id 13so2086422pfw.9 for ; Thu, 16 May 2019 09:14:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=7XoLVRfjhS6S8Tt3recnd89lCBfS8aQbdPBxOjAwbsk=; b=ZrvE9x9+Db23eixcDEP36c66jpEy9/u3uwwuyrWdAs2qSCBsVvXLV7qGQvPMS01nDZ J+ebdedOXsbKFoUEFUGAPFrLhEpmdE/2JLbJWTLFLbEf2+2XCSGm7r8ILYJ0n+XgKd/I QIBXzHsr+dqVQ+XJ+nS6bakJsQkZKd4/WCwjZILmNqEd3eKA6twTlKDjPAsmyv558DtG IXYLrQEQh/vO1tGkvlOXg27GSmkXKbuNbnjwy/BonAykqtvGzV7K6i4k9oMWo5Nycnbl cnuUx5CiSnUNR2PGQgPnKN8pFSb2r2OtLRE7OgESRLlGkXzu7JvJv+OxToGHvMQ1UZCU vLVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=7XoLVRfjhS6S8Tt3recnd89lCBfS8aQbdPBxOjAwbsk=; b=T+wX8VzXR3DPKpQvCR6bECiuKYgVEc2VGbWFFy9eGn3p2Fxs+inoC+Aw2BtmeJzGPq hwyCzucph/X1IwfKb+1dpZTz0lo5t7C0YScOLtqWfx92rkAFXUEHmaNpvngKBbZJk5Tf KS7d1UY6fClOvcyBCkfkdtkprd6+dlNJr5RhVoj6/1JgmrWzXMljmwqHrP+BYrAvNszc U+UHi6xUZdLp9y3OYEJiBC0k92uPHGDNiYVxXN1HeCHRIudwVwCMeA4pxyH9QAwm+J9e auDuSgEar7HWZCXmJ5l1DF5a+ykZ50m3K1jfpsEwS4IHPYE6CzMIKBvw+EW2Fh9zMblA mVHQ== X-Gm-Message-State: APjAAAWbaLldsjaLwC1wwQ3CtT7nT9WR7AZ4ui4aT3duCqe/G/Flq5qo 6aEwXQdd043MaE5obkEuDalgrdth X-Google-Smtp-Source: APXvYqxmxmLMIchDHIrlj+bj9dc1ZxEaCWZ/A3iUOgaV/+PszOso9tQE+qXjRV20mSUrF2KEfXPEZw== X-Received: by 2002:a63:dc09:: with SMTP id s9mr9711281pgg.425.1558023273668; Thu, 16 May 2019 09:14:33 -0700 (PDT) Received: from ?IPv6:2620:15c:2c1:200:55c7:81e6:c7d8:94b? ([2620:15c:2c1:200:55c7:81e6:c7d8:94b]) by smtp.gmail.com with ESMTPSA id q4sm7366580pgb.39.2019.05.16.09.14.32 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Thu, 16 May 2019 09:14:33 -0700 (PDT) Subject: Re: Kernel UDP behavior with missing destinations From: Eric Dumazet To: Willem de Bruijn , Adam Urban Cc: Network Development References: <0d50023e-0a3b-b92b-59d6-39d0c02fa182@gmail.com> Message-ID: <18aefee7-4c47-d330-c6c1-7d1442551fa6@gmail.com> Date: Thu, 16 May 2019 09:14:31 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <0d50023e-0a3b-b92b-59d6-39d0c02fa182@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 5/16/19 9:05 AM, Eric Dumazet wrote: > We probably should add a ttl on arp queues. > > neigh_probe() could do that quite easily. > Adam, all you need to do is to increase UDP socket sndbuf. Either by increasing /proc/sys/net/core/wmem_default or using setsockopt( ... SO_SNDBUF ... )