My ultimate goal is to allow VPN users to have access to my internal IPv6 network from across the intertubes. I've got a linksys WRT54GSv2 running DD-WRTv24SP1 and have configured the little guy as specified here http://www.dd-wrt.com/wiki/index.php/IPv6 and it works wonderfully over the br0 interface (LAN/WLAN bridge).

Here's the issue though, when I add an additional interface to the radvd config file on the router (specifically ppp0, for the VPN traffic), radvd refuses to start. The kicker is that on DDWRT, it doesn't give an error message, it just fails outright.

Any suggestions on where to proceed from here?

/jffs/radvd.conf:

interface br0 {
   AdvSendAdvert on;
   prefix 0:0:0:1::/64 {
    AdvOnLink on;
    AdvAutonomous on;
   };
};
interface ppp0 {
   AdvSendAdvert on;
   prefix 0:0:0:1::/64 {
    AdvOnLink on;
    AdvAutonomous on;
   };
};

The documentation I've found for radvd is slim, but if anyone has a decent idea on how to proceed I'd love to hear it.