The error with networking is going to come down to how qemu is invoked
by libguestfs.
Are you using the default ('direct') backend on both Fedora & Ubuntu?
Try doing:
guestfish get-backend
or this command if libguestfs is not installed:
./run guestfish get-backend
Next do this command, all on one line:
guestfish -v -x --network -a /dev/null run : debug sh 'exec 3<>
/dev/tcp/google.com/80 ; echo -e "GET /\n" >&3 ; cat <&3'
#
http://www.linuxjournal.com/content/more-using-bashs-built-devtcp-file-tcpip
You'll have to look for the qemu command line in the debug output.
Both the command line parameters related to the network, and the
version of qemu are of interest.
Also note that `ping' is not expected to work inside the guest, when
using the direct backend as non-root.
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
Read my programming and virtualization blog:
http://rwmj.wordpress.com
libguestfs lets you edit virtual machines. Supports shell scripting,
bindings from many languages.
http://libguestfs.org