Jack Snodgrass
2006-Jan-23 01:37 UTC
[Xen-users] setting up private networking between dom0 and domU?
I am trying to set up dom0 <->domU networking using a
virtual switch, a tap device on dom0 and a NIC on domU.
I have domU <-> domU connectvity throguth a virtual switch.
I also have domU <-> eth0 using a bridge. I''m using Xen 3.0
from Fedora FC5.
I used these commands to set up the tap0 and sw2 device:
# creating switch 2
brctl addbr sw2
brctl stp sw2 off
brctl setfd sw2 0
ifconfig sw2 up
# creating tun/tap device
tunctl -t tap0
# adding tun/tap device to bridge
brctl addif sw2 tap0
# configuring tap0 device
ip address add 192.168.3.2/29 dev tap0
ifconfig tap0 up
ifconfig shows:
[root@xen xen]# ifconfig sw2
sw2 Link encap:Ethernet HWaddr A6:44:26:ED:AC:5F
inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:259 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:7252 (7.0 KiB) TX bytes:468 (468.0 b)
[root@xen xen]# ifconfig tap0
tap0 Link encap:Ethernet HWaddr A6:44:26:ED:AC:5F
inet addr:192.168.3.2 Bcast:192.168.3.7 Mask:255.255.255.248
inet6 addr: fe80::a444:26ff:feed:ac5f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:687 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
(NOTE: look at the dropped:687 packets for tap0. I don''t know what that
means...
other than its bad. )
If I to a tcpdump -n -i sw2, and ping the tap0 device from my domU
instance, I see:
[root@xen xen]# tcpdump -n -i sw2
tcpdump: WARNING: sw2: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on sw2, link-type EN10MB (Ethernet), capture size 96 bytes
21:24:15.428994 arp who-has 192.168.3.2 tell 192.168.3.1
21:24:16.427484 arp who-has 192.168.3.2 tell 192.168.3.1
21:24:17.427558 arp who-has 192.168.3.2 tell 192.168.3.1
21:24:18.439598 arp who-has 192.168.3.2 tell 192.168.3.1
21:24:19.439673 arp who-has 192.168.3.2 tell 192.168.3.1
21:24:20.439724 arp who-has 192.168.3.2 tell 192.168.3.1
the dom0 device does not answere the ARP Who-Has request. The domU box
has the correct netmask and broadcast address defined.
I set up sw1 in a similar fashion as sw2. My two domU machine are able
to talk over sw1 just fine.
What am I missing?
Thanks - jack
_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users
Fernando Maior
2006-Jan-23 15:52 UTC
Re: [Xen-users] setting up private networking between dom0 and domU?
On 1/22/06, Jack Snodgrass <mylinuxguy@gmail.com> wrote:> I am trying to set up dom0 <->domU networking using a > virtual switch, a tap device on dom0 and a NIC on domU. > > I have domU <-> domU connectvity throguth a virtual switch. > I also have domU <-> eth0 using a bridge. I''m using Xen 3.0 > from Fedora FC5. > > I used these commands to set up the tap0 and sw2 device: > > # creating switch 2 > brctl addbr sw2 > brctl stp sw2 off > brctl setfd sw2 0 > ifconfig sw2 up > > # creating tun/tap device > tunctl -t tap0 > > # adding tun/tap device to bridge > brctl addif sw2 tap0 > > # configuring tap0 device > ip address add 192.168.3.2/29 dev tap0 > ifconfig tap0 up > > ifconfig shows: > [root@xen xen]# ifconfig sw2 > sw2 Link encap:Ethernet HWaddr A6:44:26:ED:AC:5F > inet6 addr: fe80::200:ff:fe00:0/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:259 errors:0 dropped:0 overruns:0 frame:0 > TX packets:6 errors:0 dropped:0 overruns:0 carrier:0 > collisions:0 txqueuelen:0 > RX bytes:7252 (7.0 KiB) TX bytes:468 (468.0 b) > > [root@xen xen]# ifconfig tap0 > tap0 Link encap:Ethernet HWaddr A6:44:26:ED:AC:5F > inet addr:192.168.3.2 Bcast:192.168.3.7 Mask:255.255.255.248 > inet6 addr: fe80::a444:26ff:feed:ac5f/64 Scope:Link > UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 > RX packets:0 errors:0 dropped:0 overruns:0 frame:0 > TX packets:0 errors:0 dropped:687 overruns:0 carrier:0 > collisions:0 txqueuelen:500 > RX bytes:0 (0.0 b) TX bytes:0 (0.0 b) > > (NOTE: look at the dropped:687 packets for tap0. I don''t know what that means... > other than its bad. ) > > If I to a tcpdump -n -i sw2, and ping the tap0 device from my domU > instance, I see: > [root@xen xen]# tcpdump -n -i sw2 > tcpdump: WARNING: sw2: no IPv4 address assigned > tcpdump: verbose output suppressed, use -v or -vv for full protocol decode > listening on sw2, link-type EN10MB (Ethernet), capture size 96 bytes > 21:24:15.428994 arp who-has 192.168.3.2 tell 192.168.3.1 > 21:24:16.427484 arp who-has 192.168.3.2 tell 192.168.3.1 > 21:24:17.427558 arp who-has 192.168.3.2 tell 192.168.3.1 > 21:24:18.439598 arp who-has 192.168.3.2 tell 192.168.3.1 > 21:24:19.439673 arp who-has 192.168.3.2 tell 192.168.3.1 > 21:24:20.439724 arp who-has 192.168.3.2 tell 192.168.3.1 > > the dom0 device does not answere the ARP Who-Has request. The domU box > has the correct netmask and broadcast address defined. > > I set up sw1 in a similar fashion as sw2. My two domU machine are able > to talk over sw1 just fine. > > What am I missing? > > Thanks - jack > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >Hi, Did you realize you have same MAC address for both sw2 and tap0? What about your eth0? May be you have a conflict up there... -- Bye, Fernando Maior LPIC/1(31908) LinuxCounter(391325) _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Alexander Myodov
2006-Jan-23 17:32 UTC
Re: [Xen-users] setting up private networking between dom0 and domU?
Hello, I am also very interested in running Windows in XEN environment under VT or Pacifica, so I hope you let me ask several questions...> > To what avail? > > Being able to install unmodified non-graphical (server)systems is a fine > > thing; graphical systems like W2K3/XP is another talk. > > No Xen-aware video drivers are available. In a couple of threads, I''ve > > argued that Nvidia is interested in developing such a driver, but won''t > > do it until deemed nessesary. It will only happen with applied pressure.What is known about Nvidia plans - do they plan to develop a dom0-only, or maybe even a domU drivers as well? Do I understand properly that with proper domU-drivers it will be possible... maybe even run OpenGL/DirectX software under guest Windows? As far as I understand, ATI drivers were made compatible with dom0, but no domU yet - so is Nvidia behind ATI in this area yet?> There are three aspects here:Windows emulation question is pretty interesting... The question about video cards has been discussed - but what about other drivers and hardware? Is sound card virtualization now working in any form (at least in "3"-mode, by emulation)? With pretty good state of opensource sound support in Linux, it should be possible to allow soundcards using in domU - but how is it now, and what are the nearest plans in this area? And, probably, the most important: how hard drive is emulated for guest Windows? Should it use a dedicated drive, a dedicated partition, or maybe it requires an "image" file (visible to domU-Windows as hard drive, but stored as a file on a real FS for dom-Linux)? Or maybe even file-level access is virtualized, so that we can be able to have paths like /var/Windows/Program Files/ on our Reisers and Exts and to distribute Windows files over LVM? And also: currently mostly Intel VT is being discussed, as the only available on the market now. But will advanced AMD Pacifica''s features help with anything of above (video/audio/hard disk), or they will give only performance benefits? -- With best regards, Alexander mailto:maa_subscriptions@sinn.ru _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Mark Williamson
2006-Jan-23 17:47 UTC
Re: [Xen-users] setting up private networking between dom0 and domU?
> What is known about Nvidia plans - do they plan to develop a dom0-only, > or maybe even a domU drivers as well?dom0 3D drivers are certainly easier (these should also work in a domU that has access to PCI graphics card, once PCI-passthrough is working again - someone will have to figure out how to make X behave correctly, tho). domU drivers would ideally be more generic than a particular manufacturer''s drivers, although there is a performance / generic-ness tradeoff here.> Do I understand properly that > with proper domU-drivers it will be possible... maybe even run > OpenGL/DirectX software under guest Windows?In theory, certainly. It just requires somebody to design and implement a 3D virtual graphics interface *and* write the appropriate Windows driver.> As far as I understand, ATI > drivers were made compatible with dom0, but no domU yet - so is Nvidia > behind ATI in this area yet?I''m not sure the patches to the ATI driver to make it behave itself under Xen have been upstreamed yet. Once Xen is in the mainline kernel and its popularity becomes apparent, hopefully both manufacturers will decide its worth testing under Xen.> Is sound card virtualization now working in any form (at least in > "3"-mode, by emulation)?I''d imagine that''s reasonably easy to make work for VT guests. Paravirt guests need to use network sound daemons at the moment, (artsd, esoundd, or use FreeNX if you can make it work). A number of people have been looking at paravirtualised sound drivers for native Xen guests.> And, probably, the most important: how hard drive is emulated for > guest Windows? Should it use a dedicated drive, a dedicated partition, > or maybe it requires an "image" file (visible to domU-Windows as hard > drive, but stored as a file on a real FS for dom-Linux)?Right now the emulation is provided by userspace in dom0, so it could be any of those options. In future I understand it''s likely to be provided by some kind of shadow IO domain that will run alongside the VT domain and emulate device accesses, using the normal paravirtualised interface to dom0 to actually transfer data. This option should help with performance and also make live migration, suspend/resume, etc closer to the process required for native domains.> Or maybe even > file-level access is virtualized, so that we can be able to have paths > like /var/Windows/Program Files/ on our Reisers and Exts and to > distribute Windows files over LVM?You''d want something like my XenFS for this. It''ll be quite a long time before a XenFS client for Windows is available, it''ll be Linux-only to start with.> And also: currently mostly Intel VT is being discussed, as the only > available on the market now. But will advanced AMD Pacifica''s features > help with anything of above (video/audio/hard disk), or they will give > only performance benefits?Device emulation will be rather similar for both. I get the impression Pacifica has more features for safely exposing real devices for dedicated access by guests, but I''m not certain on this. Future iterations of virtualisation-aware hardware are likely to include more support for virtualisation. Smart NICS (like Infiniband) are already well disposed towards efficient virtualisation, since they provide virtual network interfaces in hardware. HTH, Mark -- Dave: Just a question. What use is a unicyle with no seat? And no pedals! Mark: To answer a question with a question: What use is a skateboard? Dave: Skateboards have wheels. Mark: My wheel has a wheel! _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users