Have you tried running a Wireshark capture on that employee's computer to confirm if it's trying use DirectAccess over IPv6?
Frank -----Original Message----- From: ipv6-ops-bounces+frnkblk=iname....@lists.cluenet.de [mailto:ipv6-ops-bounces+frnkblk=iname....@lists.cluenet.de] On Behalf Of Kurt Buff Sent: Saturday, December 19, 2015 3:38 PM To: ipv6-ops@lists.cluenet.de Subject: Curious situation - not urgent, but I'd like to know more All, I ran into an interesting situation some months ago which still baffles me, and though I was able to work around it, I expect it will happen again. We implemented MSFT DirectAcess at our company quite some time ago (using 2008R2 and Forefront 2010), and it works extremely well. At least it worked well for everyone until one of the employees got his Comcast connection upgraded, and then DirectAccess didn't work for that employee any more. We proved that if he tethered to his cell phone, that would work, and if he used an SSL VPN client while on his Comcast connect that would work, but DirectAccess would not work at home. Finally, I discovered that his Comcast-installed router was handing our IPv6 addresses on his home LAN. Turning that off enabled DirectAccess to work again. We do not have an assigned IPv6 block from our ISP, though of course MSFT OSes use it, and auto-assign themselves addresses, but for now we're ignoring it. Has anyone run into this problem and solved it - not by turning off iIPv6 address assignment for the home LAN, but really solved it? If so, how did you do that? Would getting and implementing an IPv6 assignment from our ISP cure the problem, or make it worse? I've found little guidance from MSFT about DirectAccess in an IPv6 environment, though I admit I haven't been terribly diligent in my searches. Kurt