Posts from 2019

  • Simple NDP Proxy to Route Your IPv6 VPN Addresses

    If you tried setting up an IPv6-capable VPN on a VPS provider that gave you an IP range to play with, perhaps a /64 or larger, you would want to assign some of the IPv6 addresses you have to your clients. In this post, we suppose that you have the range 2001:db8::/64.

    This should be a simple process: enable the sysctl option net.ipv6.conf.all.forwarding to 1 (or whatever the equivalent is on your system), use DHCPv6 or SLAAC to assign the addresses to the clients, and then your client should have working IPv6.

    The Problem

    Unfortunately, this is not so simple. Most VPS providers are not actually routing the entire subnet 2001:db8::/64 to you. Rather, they just connect a number of VPSes onto the same virtual Ethernet network and rely on the Neighbour Discovery Protocol (NDP) to find the router.

    (Read more...)