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I have a server that is running Debian 7.2. I recently set up KVM on it, and created two VMs. Both VMs are unable to connect to the Internet. I was following a tutorial, and I'm certain I followed the instructions.

I have created a bridge for eth0, and it did appear in Virtual Manager. I'm not sure if it's because further configuration is needed on the guests, but everything in terms of networking on the host is fine.

The VM guests run Ubuntu Server 12.04, and Windows Server 2008 R2 respectively.

I can ping myself, but I cannot ping the gateway nor 8.8.8.8, so I'm assuming the guest VM isn't interfacing with the physical interface on the host?

Any ideas? I would provide diagnostics, but I'm not sure what's needed, but here's the output of ifconfig on the host:

br0       Link encap:Ethernet  HWaddr e0:69:95:63:0f:8c  
          inet addr:91.X.X.X  Bcast:91.X.X.255  Mask:255.255.255.0
          Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:952959 errors:0 dropped:158 overruns:0 frame:0
          TX packets:900163 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:114328591 (109.0 MiB)  TX bytes:253702971 (241.9 MiB)

eth0      Link encap:Ethernet  HWaddr e0:69:95:63:0f:8c  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:957386 errors:0 dropped:0 overruns:0 frame:0
          TX packets:901696 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:131742809 (125.6 MiB)  TX bytes:257467238 (245.5 MiB)
          Interrupt:20 Memory:fe500000-fe520000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:142053 errors:0 dropped:0 overruns:0 frame:0
          TX packets:142053 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:15011923 (14.3 MiB)  TX bytes:15011923 (14.3 MiB)

vnet1     Link encap:Ethernet  HWaddr fe:54:00:7a:39:a5  
          Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:86 errors:0 dropped:0 overruns:0 frame:0
          TX packets:93719 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:500 
          RX bytes:4612 (4.5 KiB)  TX bytes:21561583 (20.5 MiB)

And the contents /etc/network/interfaces:

auto eth0 lo br0

iface lo inet loopback

iface eth0 inet manual

iface br0 inet static
        address 91.X.X.X
        netmask 255.255.255.0
        network 91.X.X.0
        broadcast 91.X.X.255
        gateway 91.X.X.254
        bridge_ports eth0
        bridge_fd 9
        bridge_hello 2
        bridge_maxage 12
        bridge_stp off

I'm happy to provide more details, just let me know what I need to supply. I appreciate any help, and thanks!

Output of ifconfig on Linux guest:

eth0    Link encap:Ethernet HWaddr 52:54:00:7a:39:a5
    inet addr:91.X.X.X Bcast:91.X.X.255 Mask:255.255.255.0
    inet6 addr: fe80::5054:ff:fe7a:39a5/64 Scope:Link
    UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
    RX packets:206048 errors:0 dropped:33 overruns:0 frame:0
    TX packets:85 errors:0 dropped:0 overruns:0 carrier:0
    collisions:0 txqueuelen:1000
    RX bytes:44795642 (44.7 MB) TX ytes:4570 (4.5 KB)

lo  Link encapLocal Loopback
    inet addr:127.0.0.1 Mask:255.0.0.0
    inet6 addr: ::1/128 Scope:Host
    UP LOOPBACK RUNNING MTU:65536 Metric:1
    RX packets:372 errors:0 dropped:0 overruns:0 frame:0
    TX packets:372 errors:0 dropped:0 overrun:0 carrier:0
    collisions:0 txqueuelen:0
    RX bytes:30304 (30.3 KB) TX bytes:30304 (30.3 KB)
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are you assigning ip addresses to the host and guests static, or are you using DHCP Server ? what is the output of ipconfig and ifconfig on the guest linux and windows ? –  aseaudi Jan 7 at 11:49
    
I haven't made any change to the configurations on the guests, but I'm pretty sure it is set to manual. See my post for the output of ifconfig on the Linux guest. –  Mark Jan 7 at 11:59
    
The configuration on the Linux guest is like so: auto eth0 iface eth0 inet manual –  Mark Jan 7 at 12:10
    
since guest eth0 is not static, this means guest got ip from dhcp server which i assume is on the default gateway. this means link is up between guest and gateway. try pinging the gateway from guest. –  aseaudi Jan 7 at 13:07
    
@aseaudi Strange, but when I do ping the gateway from the guest, I get a reply that the host destination is unreachable. –  Mark Jan 7 at 13:17

1 Answer 1

You say this is a server. Have you asked your provider? It's very possible that your provider is limiting you to a single MAC address per port.

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