After following the instructions in fqa 8.9.1 about porting to amd64, I found everything works well except network. It gives ipconfig: /net/ipifc/clone: bind ether /net/ether0: '/net/ether0' cs: file not exist during boot. However, my netcard works well in original 386 9front. Any solutions?

what is the model of the NIC? it may be that the driver is not enabled yet in the amd64 kernel config, if no one has tested it yet.

It is RTL8168. Maybe the driver is not enabled. How to edit kernel config?

the config file for the pc64 kernel is /sys/src/9/pc64/pc64. you just need to uncomment the line that says '# ether8169 pci ethermii'. you should refer to https://code.google.com/p/plan9front/wiki/fqa7#7.2_-_Kernel_configuration_and_maintenance for information about recompiling the kernel after editing the config file.

Solved, thanks! Sorry for my silly question.

the driver for rtl8169 family (including rtl8168) is now enabled by default in pc64 kernel config. thanks for your bug report and testing.