I've got KVM, qemu and virt-manager set up, and it works great, except that the "virtual network" doesn't seem to work. the guest operating systems can see the virtual "eth0" device, and DNS seems to work (they can resolve domains) and the guest can send data, but nothing is returned. Bascially, incoming traffic isn't working. This is the case with Windows and Syllable, the two system I have run as guests. I am running Fedora Core 8. Any helps greatly appreciated.

Could you explain exactly what virt-manager is?

My knowledge of KVM, qemu is from:

"QEMU (The Kernel Virtual Machine) and Windows Vista." at:

virt-manager is just an app for managing virtualized machines.
http://virt-manager.et.redhat.com/

KVM is kernel support for hardware virtualization features, but it's not really important, just a "backend" of sorts that QEMU uses for speed gains.

cyanide_will,

did you figure out how to fix your network problem with qemu? i'm having the similar issue like yours.

thanks

G'day, I don't know how much you know about networking and QEMU/KVM, or whether you're using user mode networking or another mode, but: if you don't specify what sort of networking, you get user mode. User mode allows you to connect to external TCP/UDP resources, but no other protocols (e.g. you can't ping), and acts like a firewall.

There's a reasonably simple summary of networking in QEMU on Wikibooks, with more information on the #qemu Wiki. The Wikibooks page tells you how to set up incoming ports with user mode networking, and also how to set up a TAP interface for full networking capabilities if you require that.