[libvirt-users] Can't NAT in KVM

[Borden Rhodes]

Thank you for the tips. There was nothing of interest in the libvirt
logs and dnsmasq seems to be installed correctly, but perhaps this
configuration information will help:

LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
HOME=/root USER=root LOGNAME=root QEMU_AUDIO_DRV=spice /usr/bin/kvm -S
-M pc-0.15 -cpu
core2duo,+lahf_lm,+osxsave,+xsave,+sse4.1,+pdcm,+xtpr,+cx16,+tm2,+est,+vmx,+ds_cpl,+dtes64,+pbe,+tm,+ht,+ss,+acpi,+ds
-enable-kvm -m 2048 -smp 2,sockets=2,cores=1,threads=1 -name
KubuntuLiveCD -uuid bfe78349-5409-d439-3ba5-545ada8727bc -nodefconfig
-nodefaults -chardev
socket,id=charmonitor,path=/var/lib/libvirt/qemu/BootDiskTest.monitor,server,nowait
-mon chardev=charmonitor,id=monitor,mode=control -rtc base=utc
-no-reboot -no-shutdown -device
piix3-usb-uhci,id=usb,bus=pci.0,addr=0x1.0x2 -device
virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x5 -drive
file=/home/borden/kubuntu-12.04-desktop-i386.iso,if=none,id=drive-ide0-1-0,readonly=on,format=raw
-device ide-cd,bus=ide.1,unit=0,drive=drive-ide0-1-0,id=ide0-1-0,bootindex=1
-netdev tap,fd=20,id=hostnet0 -device
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:e3:80:11,bus=pci.0,addr=0x3
-chardev pty,id=charserial0 -device
isa-serial,chardev=charserial0,id=serial0 -chardev
spicevmc,id=charchannel0,name=vdagent -device
virtserialport,bus=virtio-serial0.0,nr=1,chardev=charchannel0,id=channel0,name=com.redhat.spice.0
-spice port=5900,addr=127.0.0.1,disable-ticketing -vga qxl -global
qxl-vga.vram_size=67108864 -device
intel-hda,id=sound0,bus=pci.0,addr=0x4 -device
hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6

It turns out when I was poking through dmesg that I discovered that
Firestarter was, indeed, blocking the virtual machines from getting an
IP address. Which ports/services do I have to open in the firewall to
let DHCP do its work? I can't find anything in the documentation which
says that firewalls can cause problems. Perhaps someone should mention
that?

The problem isn't quite solved yet. Although the virtual machines can
an IP address, they cannot connect to the Internet. The connections
time out when I try to connect out. Suggestions?

With thanks,

Borden