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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 304D4C43603 for ; Thu, 12 Dec 2019 11:44:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EDE3B20663 for ; Thu, 12 Dec 2019 11:44:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="H7VNdAkE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729034AbfLLLo4 (ORCPT ); Thu, 12 Dec 2019 06:44:56 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:57556 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726492AbfLLLoz (ORCPT ); Thu, 12 Dec 2019 06:44:55 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:Content-Type:MIME-Version: Message-ID:Subject:To:From:Date:Reply-To:Cc:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=bzYtROeLHTdDI+24acxdpnB6/wC/k0aaf6KB5TG5RzE=; b=H7VNdAkEOXGERhUu41O4wZVHX dHi5lm19QAcrJxvMviJ7L2Os1hlzzCb6BV+Lmgf6BVAT/y1G0iLKaUVsyjq4fbA5hf91qkdB+epmN d4iIIpOws2NJkIYJ+ZlwLJ1M0RVRh926ZVePMLyDkW3DT7WAUHHqnwg+hiFtVP+siC2EHafKxhfWW w0ZMr10nw6oPNksqzvaxZ4Imt50zcnBCDvqPpaiySBz7JDx/KAgooGPjFRQ3wCxChxuOI7m36iAck qgyruYpSba+ye6Z7FMMnwcKs0fKXJVkBaMAcmlKb8lb4kv5dP3vlzAJzkJknxnIrlmvJsD8YtCFlg SYaW5AoqA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:51952) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ifMto-0006PF-Ts for netdev@vger.kernel.org; Thu, 12 Dec 2019 11:44:53 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1ifMto-0006k4-CX for netdev@vger.kernel.org; Thu, 12 Dec 2019 11:44:52 +0000 Date: Thu, 12 Dec 2019 11:44:52 +0000 From: Russell King - ARM Linux admin To: netdev@vger.kernel.org Subject: v5.2: stuck ipv4 redirects Message-ID: <20191212114452.GF25745@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, I'm seeing a problem with ipv4 redirects seemingly not expiring. I have: - A VM running a 5.2 kernel, with IP address 192.168.0.251/23, default route 192.168.0.254. - The main router at 192.168.0.254/23. - A second router which was at 192.168.1.59/23, but which I moved to 192.168.0.245/23. Behind this is a subnet 192.168.253.252/30. The VM at some point received a redirect from 192.168.0.254 for 192.168.253.254, telling it to redirect to 192.168.1.59. Since the IP change of the second router, the VM has been unable to contact 192.168.253.254, but can contact 192.168.253.253. What I see via tcpdump is: 11:34:48.549410 ARP, Request who-has 192.168.1.59 tell 192.168.0.251, length 28 I haven't found a way to view any information on the redirects that the VM kernel has accepted. The `ip' tool doesn't seem to have any way to access that information (or I'm missing something.) Any ideas what is going on, how to inspect the kernel's state from userland wrt redirects, and how this can be solved without rebooting? Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up