Having used Linode and CentOS for years I have never had a problem quite like this. Sure sounds like the IPv6 is misconfigured in the DHCP server or is in use somewhere. Some things I would try are: 1. Set "Auto configure networking" in your config profile and reboot. 2. Try to assign the adddress static. 3. Ask Linode to assign you a new IPv6 4. Wait for Linode to fix the problem. Mike