[CentOS] KVM/NAT help requested

Fri Feb 21 20:40:24 UTC 2014
Les Mikesell <lesmikesell at gmail.com>

On Fri, Feb 21, 2014 at 1:55 PM, david <david at daku.org> wrote:
> Dear Linux Gurus
> I'm having problems with KVM and networking.  My guest cannot use NAT
> through the host's connection.  This is what I've done:
> I installed a new version of Centos 6.5 on the hardware.  Starting
> with a Net-Install, I selected the Virtual Hosting, and later added
> "Desktop".  I ran "yum update" with some reboots until nothing needed updating.
> The host networking is IPV4 only, using DHCP.  (A different box on my
> home network provides DHCP and is a gateway to the internet.  I have
> a reservation in that DHCP so that the host always gets a known IP address)
> Using a Gnome desktop, as a non-root user, I installed Windows 7 Pro
> from an image of an ISO I had copied onto the host.  In the
> "Networking" configuration, I chose "DEFAULT".  The documentation of
> KVM seems to imply that it should give me a NAT'ted interface to my
> host's connection (I wasn't worried about performance at this point).
> When the installation was complete, Windows tries to configure the
> network.  Running the Windows command line "IPCONFIG" program, the
> Windows guest program does get an IP address from the host
> (192.168.122.xxx), but the guest cannot communicate to the outside
> world.  I can ping the host, but nothing else.
> Is there some other magic sauce, perhaps in the IPTABLES of the host,
> that will allow the guest to use the internet?  I'm baffled.

Do you have ip_forwarding enabled in sysctl?


   Les Mikesell
    lesmikesell at gmail.com