From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B5091C2E; Mon, 22 Jan 2024 04:10:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705896623; cv=none; b=THlAc7t9Wu2hVK/DmCrn3zGhMPfBYH+nwoMEnUX+5lvStdGWIffR10aS7FrSONWe1kHCpcTtmRy6n4UbgZl4UTVnQhMHa0AGBs6DolZXOgpQyPqGtt8ZyuiXMTS63Le1bzyNZOkpDZaPkqEiZHNAYUtUPbrDS6e/6DwxPsk3z/g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705896623; c=relaxed/simple; bh=za0u5GnYHE4ehHb3iprv2PuIL+6HBFUS4n1kw0KU1vg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XK8rFu4PGZYbsTtJnnFCr1V+d5CrSuZy3O60KoqqxXvLzy4KgbqkJW+0tLJoltI9MP69OWoXzisz7hG/LWwcqCDXoKLWPBLKnJ1WNLhyCyPdiitJIRGrxeCn20uNo8Y5aEnCZxUR/WuYhhy8NjTPyXmfisAZCzm2jFu7RTWukos= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tngkpeMG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tngkpeMG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45AE1C433F1; Mon, 22 Jan 2024 04:10:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1705896622; bh=za0u5GnYHE4ehHb3iprv2PuIL+6HBFUS4n1kw0KU1vg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=tngkpeMG1j8UleIoz3SnK5YgUv+HmMy8IqPn/d5yxgiJ9x3TNPFlMMPY3naHJ9fxW cn3wTZ9MIC1lnJUAW+BNzG/8A5Qvdq8muNhKhsYGnxYrEolMYrTZcyt+qLNhQaLsNr KiCr80TY3nE2M/muam+BZujmYynP6SHOyokgRhtMF13Zs5ajLGMzKcxRoQVtqPfN9Y vmqAygSsD9HVZ7gqusE2aHiRVYMoQQaWBPuHvmsE55OqbE0+SHFe5jC6uTYgU6ZgHc ksGdaXoWaXIINElPpdWyUK8Ws/9UGGHUpHDfELW21Xcjr7B76Q/Y+yvNHAiJSraqU4 QRfx4Iaf0jeMA== Message-ID: <90209854-8515-4f1e-8d6b-0182c8cab7ea@kernel.org> Date: Sun, 21 Jan 2024 21:10:20 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [Discuss]iproute2: ipv6 route add fail Content-Language: en-US To: gaoxingwang , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org Cc: liaichun@huawei.com, yanan@huawei.com References: <20240105094255.1498461-1-gaoxingwang1@huawei.com> From: David Ahern In-Reply-To: <20240105094255.1498461-1-gaoxingwang1@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 1/5/24 2:42 AM, gaoxingwang wrote: > Hello everyone, > > Here is a particular problem with routing. > Sometimes users can run the ip -6 route command to add a route whose destination address is the same as the gateway address, and it can be successfully added. However, adding another route with the same gateway address will fail later. > > Example: > # ip -6 route add 2409:8080:5a0a:60c7::7/128 via 2409:8080:5a0a:60c7::7 dev eth2 > # ip -6 route add 2409:8080:5a0a:60c7::8/128 via 2409:8080:5a0a:60c7::7 dev eth2 > RTNETLINK answers: No route to host > > Does the kernel not support this application scenario? > Or should the kernel not allow routes with the same destination address as the gateway address to be added so that other more meaningful routes can be added successfully? > > This question puzzles me, thank you very much if your can reply. try running `perf record -e fib6:*` and then run both route commands above. After both have run, Ctrl-C on perf and then run `perf script`