add ipv6

# You will need root access for this commands
# These things shown here are not correct according to some RFCs (e.g. IPv6 NAT), but I will do them anyway, because I can not guarantee, that my pi will get a whole /64 subnet as it should from the upstream router
# I assume, that you did not change anything in iptables. If you did, you should be able to set the settings correctly for IPv6 on your own.

# USE CAUTION: I DID NOT SECURE ANYTHING IN THIS SETUP! I AM NOT RESPONSIBLE FOR ANY DAMAGES CREATED BY THIS SCRIPT! USE IT AT YOUR OWN RISK! I USED A SECOND SCRIPT FOR SECURING THE PI, WHICH IS NOT PROVIDED HERE!

# I will use fc72:4444:26dd:98c9::1 as address for the pi
# use your own settings:
export IPV6_SUBNET="fc72:4444:26dd:98c9::"
export IPV6_SIZE="/64"
export PI_ADDRESS="${IPV6_SUBNET}1"
export IPV6_CIDR="${IPV6_SUBNET}${IPV6_SIZE}"

echo USE CAUTION: I DID NOT SECURE ANYTHING IN THIS SETUP! I AM NOT RESPONSIBLE FOR ANY DAMAGES CREATED BY THIS SCRIPT! USE IT AT YOUR OWN RISK! I USED A SECOND SCRIPT FOR SECURING THE PI, WHICH IS NOT PROVIDED HERE!
read -p "Are you sure? " -n 1 -r
echo    # (optional) move to a new line
if ! [[ $REPLY =~ ^[Yy]$ ]]
then echo "Aborting!"
    exit
fi

if [ "$EUID" -ne 0 ]
  then echo "Please run as root"
  exit
fi

# adding listen address to dnsmasq
echo "listen-address=${PI_ADDRESS}" >> /etc/dnsmasq.d/090_ipv6.conf

# adding new static address to /etc/network/interfaced.d/interfaces (unfortunately /etc/dhcpcd.conf is overwritten by raspap)
echo "auto wlan0" >> /etc/network/interfaces.d/interfaces
echo "iface wlan0 inet6 static" >> /etc/network/interfaces.d/interfaces
echo "    address fc72:4444:26dd:98c9::1/64" >> /etc/network/interfaces.d/interfaces

# setting iptables rules
ip6tables -A POSTROUTING -t nat -j MASQUERADE

# install radvd (comparable to dhcp, well for the inexperienced at least) and enable it (you can use dhcpv6 as well, but some newer devices do not support it anymore)
apt update && apt install radvd
cat <<EOF >> /etc/radvd.conf
interface wlan0 { 
        IgnoreIfMissing on;
        AdvSendAdvert on;
        MinRtrAdvInterval 3; 
        MaxRtrAdvInterval 10;
        prefix ${IPV6_CIDR} { 
                AdvOnLink on; 
                AdvAutonomous on; 
                AdvRouterAddr on; 
        };
        RDNSS ${PI_ADDRESS} {};
};

EOF
systemctl enable radvd

# configure /etc/sysctl.conf
echo "net.ipv4.ip_forward=1" >> /etc/sysctl.conf
echo "net.ipv6.conf.all.forwarding=1" >> /etc/sysctl.conf

echo "DONE! Reboot to apply the changes!"

Hello,
The package is ip6tables not ip6tabels :)

Hello, The package is ip6tables not ip6tabels :)

Thats correct. Thanks you