ifconfig as of Debian stretch uses a different output format. This breaks
enumeration of devices in netcardconfig line 576.

Continuing to use ifconfig, the line should be changed to:

/sbin/ifconfig -a | awk ' !/^\s/{sub(/:/,"",$1);IFACE=$1} /Ethernet/{if (IFACE
!~ /^vmnet/) print IFACE" "$2}'

Unfortunately, this no longer works with ifconfig as of jessie.

Therefore, I suggest switching to ip(8):

ip link show | awk ' !/^\s/{sub(/:/,"",$2);IFACE=$2} /link.ether/{if (IFACE !~
/^vmnet/) print IFACE" "$2}'

This works on both jessie and stretch.