Software Deployment

I'm running DirectAccess on Server 2012 R2. The endpoints are all Windows 8.1 Enterprise. DirectAccess is working properly - I can ping and RDP into offsite machines. However, when I try to push the SCCM client, nothing happens. The SCCM server can ping the client and it returns the correct IPv6 address. I believe the client-side incoming firewall settings are correct, but I'm not sure because it doesn't seem to be even getting that far. Here's what I see in CCM.log on the server: http://pastebin.com/tdbUeFGZ

It doesn't seem to recognize that the computer is on the network, even though it can ping it. Is this a boundary problem? I have set a boundary with the IPv6 prefix, although I am not sure it's the correct prefix (I'm a total noob with IPv6) - I stole it from the computer properties of another computer with DirectAccess connectivity. To be clear, it's only client push that seems to be failing. Client machines can pick up deployments and everything, but I understand that client-initiated actions are a bit different, and that client push is server-initiated.

Are there any SCCM/DA experts who can help with this?