- First, set these sysctls:
sysctl -w net.ipv6.conf.$ext_if.forwarding=1 sysctl -w net.ipv6.conf.$int_if.forwarding=1 sysctl -w net.ipv6.conf.$ext_if.proxy_ndp=1 sysctl -w net.ipv6.conf.$int_if.proxy_ndp=1
Make sure to replace $ext_if with your external interface and $int_if with your internal interface.
- Also, ensure that you are allowing forwarding with ip6tables. You can either set it up for each interface individually, or just allow all packets:
ip6tables -P FORWARD ACCEPT
- Now, run these on your external interface:
ip link set $ext_if promisc on ip -6 route add $ext_ip dev $ext_if ip -6 route add default via $router_ip dev $ext_if metric 512
Replace $ext_ip and $router_ip as necessary.
- Next, for each machine you want to add behind your router, run these commands:
ip -6 neigh add proxy $machine_ip dev $ext_if ip -6 route add $machine_ip dev $int_if
Replace $machine_ip with the machine's IPv6 address, and replace $ext_if, and $int_if with the appropriate interfaces as above.
- Finally, run this to allow hosts behind your router to access your router's external IP:
ip -6 neigh add proxy $ext_ip dev $int_if
Replace $ext_ip and $int_if as needed.