XEN Mixed Networking (Direct Routing + Internal Bridge)

Hi Everybody, in order to setup a new server, I had to deal with this more or less troublesome topic. I want to give everybody a hint who is facing trouble with this. The Setup: – Debian Lenny (Kernel 2.6.26-2-xen-amd64) 64 Bit host and 64 Bit guests – xen-hypervisor 3.2-1 The Goal: I. have a directly routed interface for the public IPs II. create a virtual LAN between the domUs III. let the hosts on the virtual LAN talk to the outside world (those are mostly the domUs, which do not have a public IP) First, for I. and II. go ahead and apply the tutorial in [1] In addition to that, I had to perform the following operations: edit /etc/xen/scripts/vif-common.sh and add the two lines indicated vifname=$(xenstore_read_default "$XENBUS_PATH/vifname" "") if [ "$vifname" ] then if [ "$command" == "online" ] && ! ip link show "$vifname" >&/dev/null then do_or_die ip link set "$vif" down ### ADD THIS LINE do_or_die ip link set "$vif" name "$vifname" do_or_die ip link set "$vifname" up ### ADD THIS LINE fi vif="$vifname" fi Ok, now there is something you should keep in mind: While editing your domU config be sure to keep the vifname parameter SHORT!! I called it ‘mysql-mirror-vif-br’ which was way too long, which then resulted in a non-starting script. The script did not tell me anything. Not on stdout not in the logs. Now it’s ‘mymirr-vif-br’ which is fine. For III. do the following for every IP you want to have internet access from the inside of the respective domU: iptables -t nat -A POSTROUTING -o eth0 -s virtualLanIP/32 -j MASQUERADE Hope this helps someone. Cheers! [1] Hetzner Dokuwiki: http://wiki.hetzner.de/index.php/Xen_mit_Routing_und_Bridge


  • Barry

    Thanks for this update.

    I was struggling with the same problem

    One request, for us English only, people.
    Is there an English translation for your step 1 reference? (Xen_mit_Routing_und_Bridge).

    I can make out what you have done, no problem, but I’d like to make sure I did not miss something important.



  • henning

    Hi Barry,

    thanks for your comment!
    I’ll try to go ahead and translate the howto into English and make it public in a new post.


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