I have a Windows Server 2012 R2 Essentials box which is configured with the basic RRAS VPN functionality, it isn't configured as a router, this functionality is not enabled and my R2 Essentials box doesn't have the DHCP role installed (I have a gateway router to handle DHCP), it is however a DNS server as its configured as an Active Directory server.
I've noticed that when using the VPN through SSTP and other protocols, the IPv6 connectivity is broken. Clients get an IPv6 address as per the assigned prefix, but after the first hop from a tracert, it is unroutable and cannot get to the outside, so my server is not handling the IPv6 traffic properly.
My IPv6 connectivity is provided by Hurricane Electric (tunnel), this is configured at the router level with the /64 provided and dynamically pushed to clients on the LAN via radvd. On the box itself, I have disabled auto-configuration and setup IPv6 manually. IPv6 connectivity of the box itself is working fine.
When configuring IPv6 in RRAS the following are all enabled:
- IPv6 Remote Access Server [checked]
- Enable IPv6 Forwarding [checked]
- Enable Default Route Advertisement [checked]
The IPv6 prefix assigned is the /64 provided by Hurricane Electric, I am unsure if this is correct or not, seems its already configured at router level.
I do have a /48 which is not currently used and may be suitable here.
IPv4 traffic is forwarded no problem and a tracert shows the traffic can pass through, this VPN issues are limited to IPv6.
It doesn't appear to be a firewall issue as I've tested with it disabled.
I can post any route/IP information required to help solve the issue. I would appreciate any pointers/additional help on solving this IPv6 connectivity issue with my RRAS VPN.