This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-users] Sending DHCP-Offer from DomU in routed-mode doesn't work

To: Patrick Straub <pastraub@xxxxxxxxxxxxxxxx>
Subject: Re: [Xen-users] Sending DHCP-Offer from DomU in routed-mode doesn't work
From: Goswin von Brederlow <goswin-v-b@xxxxxx>
Date: Wed, 23 Sep 2009 16:24:52 +0200
Cc: xen-users@xxxxxxxxxxxxxxxxxxx
Delivery-date: Wed, 23 Sep 2009 07:27:48 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <1253698910.5686.1.camel@fuwa> (Patrick Straub's message of "Wed, 23 Sep 2009 11:41:50 +0200")
List-help: <mailto:xen-users-request@lists.xensource.com?subject=help>
List-id: Xen user discussion <xen-users.lists.xensource.com>
List-post: <mailto:xen-users@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-users>, <mailto:xen-users-request@lists.xensource.com?subject=unsubscribe>
References: <1253698910.5686.1.camel@fuwa>
Sender: xen-users-bounces@xxxxxxxxxxxxxxxxxxx
User-agent: Gnus/5.110006 (No Gnus v0.6) XEmacs/21.4.22 (linux)
Patrick Straub <pastraub@xxxxxxxxxxxxxxxx> writes:

> Hello,
> I'm currently working with Xen in routing mode. So I changed the
> xend-config file and changed the mode to:
>         (network-script network-route)
>         (vif-script vif-route)
> So by default, ip_forwarding and prox_arp is now enabled (i checked it)
> on eth0.
> My config for the domU's looks as follows:
>         kernel = "/boot/vmlinuz-2.6.26-2-xen-686"
>         ramdisk = "/boot/initrd.img-2.6.26-2-xen-686"
>         memory = "512"
>         name = "ubuntu2"
>         vif = [ 'ip=, mac=00:01:02:03:04:05,vifname=ub2.0' ]
>         disk = ['file:/.../ubuntu.9-04.x86.img,sda1,w']
>         root = "/dev/sda1 ro"
>         extra = "xencons=tty1
> Now when I start the domU domain named ubuntu2 the routes where created
> and if I specify the given Ip by myself in the Userdomain everything
> works fine and I can connect to the world.
> But now I when I'm going to run a DHCP-server on dom0 to handle requests
> from the domU's the offers do not even arrive on the vif-Interface of
> the domU (named ub2.0)?
> And I've no explanation why? I checked the iptables rules, so the
> default rules for FORWARDING also DHCP request have been set. (I also
> experimented with deleting them, reconfigure and so on) But as it shows
> no effect to the DHCP-Request and the fact that I think I should have
> seen them at least at the ub2.0 Intefaces I'm thinking that Xen is maybe
> blocking the request?
> Does anybody know how, why or what is exactly going on there?
> Thank you in advance and sorry for my bad english :)

Dhcp uses broadcast and broadcast is not routed. You need to run a
dhcp forward/proxy on the router (dom0) or use bridged mode.


Xen-users mailing list

<Prev in Thread] Current Thread [Next in Thread>