I have run into nothing but trouble with IPv6. Not that there is anything in particular that is wrong, but not all apps understand and can work with it. For example I am running a geographically dispersed cluster on a Windows server with 2008 Exchange 2007 on a Dell 2950. I am getting these odd Event Log errors 2501, 2601 and 2604.
When updating security for a remote procedure call (RPC) access for the Exchange Active Directory Topology service, Exchange could not retrieve the security descriptor for Exchange server object xxxxxxx - Error code=8007077f. The Exchange Active Directory Topology service will continue with limited permissions.
For my experience it turns out a tunnel adapter on the 2950 is mapping a DNS record on IPv6. I thought I had disabled all the IPv6 pieces but I was mistaken.
The following recipe should be what is needed to disable all pieces of IPv6 on Windows Server 2008 (As well as Vista) as well as enabling ping on IPv4.
Enable Pings, Firewall doesn't allow IPv4 pings
Server Manager / Configuration / Windows Firewall with Advanced... / Inbound Rules
Action / New Rule
Select Custom
Next
Select All Programs
Next
Protocol Type = ICMPv4
Next
Local Ip Address = Any
Remote IP Address = Any
Next
Select allow the connection
Next
Check Domain
Check Private
Check Public
Next
Name = IPv4
Finish
Network
Right Click Network Places
Select Manage Network Connections For each enabled and used NIC
Right Click - Local Area Connection - Select Properties
Networking Tab
DeSelect IPv6
Close
Disables tunneling but not the loopback interface
Regedit (For additional info http://technet.microsoft.com/en-us/library/bb878057.aspx)
Add the following key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip6Parameters\DisabledComponents
DWORD => FFFFFFFF
Change the Nic Provider Order
Network Connections
Advanced
Advanced Settings
Provider Order
Move Microsoft Windows Networks to the top