How To print net_*** variables?

[Thomas Schweikle]

I am trying to print net_* variables to console. But all I get is nothing.

echo "Network:"
echo "Interface: ${net_default_interface}"
echo "IP: ${net_${net_default_interface}_ip}"
echo "GW: ${net_${net_default_interface}_gateway}"
echo "NM: ${net_${net_default_interface}_netmask}"
echo "HN: ${net_${net_default_interface}_hostname}"
echo "DO: ${net_${net_default_interface}_domain}"
echo "BT: ${net_${net_default_interface}_rootpath}"
echo "BF: ${net_${net_default_interface}_boot_file}"
echo "DH: ${net_${net_default_interface}_dhcp_server_name}"

Prints:
Network:
Interface:
IP:
GW:
NM:
HN:
DO:
BT:
BF:
DH:

grub s loaded from tftp. Not local disks. Thus I'd assume networking
ist set up as it should be ...
Any idea?

-- 
Thomas