NetBSD in an HVM instance can't see outside world

["Michael Litchard" <michael%schmong.org@localhost>]

Whether I try to use dhcp or manually configure an ip, I can neither
ping, nor be pinged.

Here's my config file. Could someone help me troubleshoot?
#============================================================================
# Python configuration setup for 'xm create'.
# This script sets the parameters used when a domain is created using
'xm create'.
# You use a separate script for each domain you want to create, or
# you can set the parameters for the domain on the xm command line.
#============================================================================

#----------------------------------------------------------------------------
# Kernel image file.
kernel = "/usr/pkg/lib/xen/boot/hvmloader"

builder='hvm'

# Initial memory allocation (in megabytes) for the new domain.
memory = 256

# A name for your domain. All domains must have different names.
name = "hvm-netbsd"

#Network interface. By default emules a realtek 8139. For a NetBSD guest you
# have to disable re(4) and let rtk attach to use it.
# ne2k_pci emulates a pci ne2000 clone; this his cpu-hungry in dom0
# pcnet emulates a AMD PCnet-PCI controller; but it corrupts packets with
# pcn(4) under NetBSD.
#vif = [ 'mac=00:16:3e:00:00:13, bridge=bridge0, type=ioemu, model=ne2k_pci' ]
#vif = [ 'mac=00:16:3e:00:00:13, bridge=bridge0, type=ioemu, model=pcnet' ]
vif = [ 'mac=00:16:3d:00:00:13, bridge=bridge0, type=ioemu' ]

#----------------------------------------------------------------------------
# device model to use: only qemu-dm available for now
device_model = '/usr/pkg/libexec/qemu-dm'

# Define the disk devices you want the domain to have access to, and
# what you want them accessible as.
# Each disk entry is of the form phy:UNAME,DEV,MODE
# where UNAME is the device, DEV is the device name the domain will see,
# and MODE is r for read-only, w for read-write.
# For hvm domains you can only use hda to hdd. You can set extra types
# (e.g. cdrom)

disk = [ 'file:/usr/local/domU5/disk,ioemu:hdb,w',
'file:/sys/Desktop/boot.iso,ioemu:hdc
:cdrom,r' ]

#disk = ['phy:/dev/wd0i,ioemu:hdb,w']
# floppy images; this doesn't seem to work currently. Use a iso image instead.
#fda = '/home/domains/boot1.fs'

# boot device: a = floppy, c= hard drive, d= cdrom (with the disk entry
# before)
boot='d'

# By default, 'xm create' will try to open an X window on the current display
# for the virtal framebuffer. You can have the virtal framebuffer in vnc
# instead, and connect using a vnc client (using localhost:$vncdisplay)
# If vncunused is set to 1 (this is the default value), vncdisplay
# will be set to the first unused port; so it's recommended to
#nographic=0
#serial="null"
#serial="pty"
vnc = 1
vncdisplay = 1
vncunused = 0
vncconsole=0
vnclisten='0.0.0.0'
vncpasswd='abcdef'

soundhw="sb16"
fullscreen=1
#Xen emulates a PS/2 mouse, but the pointer in the guest has difficulties
# tracking the absolute position. Xen can emulate a USB tablet in addition
# to the mouse which will report the absolute position of the pointer,
# and make the mouse much easier to use.
#
usb=1
usbdevice='tablet'
#usbdevice='mouse'