From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f171.google.com (mail-pf1-f171.google.com [209.85.210.171]) by dpdk.org (Postfix) with ESMTP id A5D6D1B148 for ; Wed, 2 Jan 2019 14:05:02 +0100 (CET) Received: by mail-pf1-f171.google.com with SMTP id b85so15179421pfc.3 for ; Wed, 02 Jan 2019 05:05:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fluidic-io.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=f5SLSMGY+duwhWcvcRK/CF9Be/seGuEcsuld0Wjn4z8=; b=TWr3YOhrN3JjqHgdLWa07pkHYixudp5iAmufgVbzXM9PlxeLzw9MO784eFdy1cLP4n 65EPybmgGOo5WrE7vU4h9qxVJu5mRbgSzaN1ZUPeHUXjw6deZOGuafqMheKKhun4uK/+ q0TXWgT4qtup8goQrM2BHQ1TQCgk2+hEA9vmSsa1kd4gSGM04EO6+5mEezFdMkAd7EMC XJ+9ECaXrSk0Cz3AMSrUQLzsxVhSTrFsU3dxe0IKC0k/XiG7Mdi1z8inxvLXFS8TBavA LjKBjdhj98lKs23Z+MEdN2Erlbcp23A8V5wtTxuJAlQUBYO0xrnJKbw0lfjUO7mcmzaa jXSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=f5SLSMGY+duwhWcvcRK/CF9Be/seGuEcsuld0Wjn4z8=; b=NvQxDQMuUO8rZf73gBlsvR2aIa//McMX3yvwk579Hkve/LGyCno0XeaZ7GI1x53q4s i0DVwzG9z905NTWCyeAUB20K+UUZ4wAtqhdfaUTHyd1KG56PM6cquxQgAzVqH6pyFuD6 ZtBYj6FOO0ALUySEmjZgweNPDIySmxUNw91JlZCa6dRE5034CmYm9b20Utk5SIaI5v6P iXvPZfOFVL+ARfQh5UL4quQvc1M99BqoPhxIwpEx97BP6KIHt51ZIy4IXma8V+Gsmmst oWb54rOhDdV9aLPLCgs4du/h5tej2Y13I/NPDBewlPVSEjO/H4KRwWymTvw0Xgzbwqe2 2DBQ== X-Gm-Message-State: AJcUuketdJTiiM2a7e1qXXmZzhl+YC7jmTVnXz7jcjnrMpQdfFmrAvVc GT85fgaAtS2eM2edCCznJlNp8xzuhpqqbtnuB5TiaqswSJOa7A== X-Google-Smtp-Source: ALg8bN5wz7w1tqPpmp3r1oixk7abFnj8Rq431Qbu8m+8Z7rZegI7T3sYvEk7dCqJPomAqB9RnzuSTV4ZRSDzA5tBhWI= X-Received: by 2002:a63:f65:: with SMTP id 37mr13369941pgp.238.1546434301623; Wed, 02 Jan 2019 05:05:01 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: DoHyung Kim Date: Wed, 2 Jan 2019 22:04:50 +0900 Message-ID: To: Jay Rolette Cc: users Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.15 Subject: Re: [dpdk-users] Weird phenomenon involving KNI X-BeenThere: users@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK usage discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jan 2019 13:05:02 -0000 It's not relevant to DPDK at all. I was trying to put two NICs in a host to single subnet, and even w/o DPDK involved, the NICs didn't work properly. Googling turned out that one can't use multiple NICs in a Linux host in single subnet under the default, out of the box, configuration. I guess many of subscribers in this mailing list should already be familar w/ the problem. But I describe how I've solved the problem below in the hope that it may be helpful to someone like me: If one wants such a network setup, one needs to tweak routing rules together w/ a few changes to the way ARP is handled. An interesting point here is one needs to set routing rules correctly in order to just get ARP replies work as intenteded, though ARP replies are not strictly relevant to the outgoing packets. Please refer to the following doc: https://access.redhat.com/solutions/3056= 4 In summary, each NIC needs to have a separate routing table and a routing rule linking the table w/ the IP address of the NIC. I added arp_ignore =3D 1 together w/ arp_announce =3D 2 since other docs on= the ARP flux problem suggests doing so. DoHyung 2019=EB=85=84 1=EC=9B=94 2=EC=9D=BC (=EC=88=98) =EC=98=A4=ED=9B=84 9:38, Ja= y Rolette =EB=8B=98=EC=9D=B4 =EC=9E=91=EC=84=B1: > On Tue, Jan 1, 2019 at 4:05 AM DoHyung Kim wrote= : > >> It was a consequence of the well-known behavior of Linux kernel regardin= g >> ARP handling when multiple NICs are on the same subnet. >> > > What solution did you end up going with? > --=20 DoHyung Kim Fluidic Inc.