Recently we had an issue with a site where OSD was taking long time on random basis. When I was trying to gather more information about similar issues I come across below article. This article very well describe IP6To4 tunnel adapter and it’s impact in network / AD environment.
The OSD was extremely slow on random basis. Even few MBs file were taking hours to download. As described in above article, the public IP address was being used in this site as well. The IP 6to4 tunnel adapter was also enabled on SCCM server and client workstations. Once we disabled the IP 6to4 tunnel adapter on SCCM server the build started working fine. We have also disabled this adapter on all workstations via GPO as it may also impact network performance. It’s over a month now and issue has not been reported back.