lxd-openwrt/files/etc/uci-defaults/70_fill-dhcp-checksum

#!/bin/sh

cat >> /etc/firewall.user << EOF

# Fill DHCP checksums, try to work-around broken DHCP clients (such as FreeBSD).
# It requires iptables-mod-checksum which is installed by default in lxd-openwrt.
if [ -e /usr/lib/iptables/libxt_CHECKSUM.so ]; then
    iptables -t mangle -A OUTPUT -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill
fi

EOF