From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: Re: FAQ on linux-kvm.org has broken link Date: Tue, 30 Jul 2013 14:25:46 +0200 Message-ID: <20130730122546.GA7239@stefanha-thinkpad.redhat.com> References: <20130730011852.GC27878@belle.intranet.vanheusden.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: kvm@vger.kernel.org To: folkert Return-path: Received: from mail-wi0-f180.google.com ([209.85.212.180]:48109 "EHLO mail-wi0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751300Ab3G3MZu (ORCPT ); Tue, 30 Jul 2013 08:25:50 -0400 Received: by mail-wi0-f180.google.com with SMTP id f14so2036923wiw.13 for ; Tue, 30 Jul 2013 05:25:49 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20130730011852.GC27878@belle.intranet.vanheusden.com> Sender: kvm-owner@vger.kernel.org List-ID: On Tue, Jul 30, 2013 at 03:18:53AM +0200, folkert wrote: > The link at: > http://www.linux-kvm.org/page/FAQ#My_guest_network_is_stuck_what_should_I_do.3F > pointing to: > http://qemu-buch.de/cgi-bin/moin.cgi/QemuNetwork > is broken: it gives a "Internal server error" message. > > Please someone point me to the correct location as I'm struggeling with > a VM losing connectivity all the time. Hi Folkert, I have updated the wiki to point to http://qemu-project.org/Documentation/Networking. The original link seems to be down. If you keep losing network connectivity you may have a MAC or IP address conflict. The symptom is that network traffic is intermittent - for example, ping might work but a full TCP connection does not. This happens when two guests are configured with identical MAC or IP addresses on the same bridge or subnet. They will "fight" over the MAC or IP address and you will not be able to reliably communicate with those guests. The tool for solving networking issues is often tcpdump. Run tcpdump inside the guest to verify it is receiving traffic or investigate a failed connection. Run tcpdump on the host - especially if you are using -netdev tap - to inspect the traffic being forwarded on behalf of the guest. If you let libvirt set up networking for you all should be fine. If you run qemu manually or customized the domain XML, then it's possible you have a misconfiguration. Feel free to post the details so someone can help you. Stefan