/etc/sysctl.conf

net.ipv4.ip_forward=1
net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.all.rp_filter=0
net.ipv6.conf.all.disable_ipv6=1
net.ipv6.conf.default.disable_ipv6=1
net.ipv4.conf.all.proxy_arp=1

sysctl -p