Has anyone managed to install a Centos6 or Centos7 in Washington or Orgegon, or anywhere else that Comcast has deployed the IPV6to4 routers. The router in question is a Xfinity DCP3939 Router with Wireless, and I'm trying to get a Centos system working behind that router (with a wired connection), and enable SSH access from outside. Does one have to enable both IPV6 and IPV4? Can I enable IPV6 after install, or do I have to restart the installation from scratch (it has Centos6 installed via an earlier IPV4 router). How does one configure the router so that its DHCP system awards a known address to that machine, and how to forward port 22? The extra problem is that I'm trying to advise the owner of this configuration remotely. Behind that same router he has a working Windows 7 machine, and I can use Team Viewer to view the router's configuration from "inside". Any assistance would be appreciated. Comcast is of no help. David