Comment 1 for bug 774474

After more investigation, I found the root of the problem is that the firmware files "rtl_nic/rtl8168d-2.fw" and "rtl_nic/rtl8168d-1.fw" were not being properly installed by "d-i hw-detect/load_firmware boolean true". Without the firmware loaded, the interface has the unfortunate tendency to go down repeatedly.

Although these files are located in "ubuntu/pool/main/l/linux-firmware/linux-firmware_1.52.tar.gz" and "ubuntu/pool/main/l/linux-firmware/linux-firmware_1.52_all.deb", they are not included in "ubuntu/pool/main/l/linux-firmware/nic-firmware_1.52_all.udeb", which I believe may be the root of the problem.

I did a workaround for this by creating a tar file of the required firmwares and downloading it with the following preseed commands:

d-i preseed/early_command string cd /lib/firmware; \
wget http://pxeserver/pxe/ubuntu/11.04/desktop/common/realtek-firmware.tgz; \
tar zxvpf realtek-firmware.tgz; \
modprobe -r r8169; \
modprobe r8169; \
udhcpc