I've been running xen for a few weeks now on an Ubuntu 12.04 server. I've got 3 guests: a Windows Server 2003 guest, an Ubuntu guest, and a Windows 7 Guest. My Server 2003 guest seems to work fine; I can ping it from the network, the hostname resolves correctly, and it can see the internet. This guest is attached to xenbr0, and its IP is

My Win7 guest is what is driving me crazy. I use the same configuration script as a base, changing the important parts (hostname and boot disk, mainly). It installed correctly, and is currently running, but I am unable to ping this guest. It's hostname is "alexander", with an IP of It is also using xenbr0. The guest can ping the firewall and various IP addressess, but seems unable to resolve hostnames.

Now heres the weird part: when I use rdesktop (RDP client) from my laptop (not the xen host) to connect to alexander, it works just fine. It apparently resolves the hostname fine, and does the same with the IP address.

So, can someone tell me why I can access this guest using RDP, but not using ping, nslookup, traceroute, etc? It's apparently invisible to all but RDP. Also, is it okay to use two guests on the same bridge, or do i need different ones for each guest?

Thanks in advance for any help.



presumably xenbr0 is bridged to the physical adaptor, eth0, and you're not using natting or routing?

can you run tcpdump on the host and see what traffic is passing through xenbr0?

is the windows guest responding to arp? is the windows guest blocking traffic due to firewall - can you temporarily turn it off safely?

yes, it is fine to have multiple VMs bridged to the same virtual adaptor, but of course the VMs must have different mac addresses to each other and to the host.

  • After struggling (and failing) to make a properly formatted comment, i discovered it was the windows firewall rules. I'm going to go turn in my geek badge now. Thanks a ton for your help, I really appreciate it. EDIT: though it may have also been when I deleted an arp entry. Oh well, you've solved my problem in any case. thanks again. – zymhan Jul 5 '12 at 22:13

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