in file /etc/default/grub variable GRUB_CMDLINE_LINUX
/etc/default/grub
GRUB_CMDLINE_LINUX
ip=<ipaddress>:<server-address unused for luks>:<gateway>:<netmask>:<hostname>:eth1:static
in file /etc/mkinitcpio.conf add to hooks dropbear encryptssh
/etc/mkinitcpio.conf
dropbear encryptssh