A common issue we see in support is unbinding or disabling IPv6 on network interfaces. Unbinding IPv6 is one of those things where you never know how it’s going to manifest, but the outcome is rarely the desired one. Based on http://technet.microsoft.com/en-us/network/cc987595.aspx here is a running list of acknowledged issues identified by product support / Windows product teams when disabling IPv6 by unchecking IPv6 checkbox, broken down by technology:
Unchecking the IPv6 checkbox in the GUI exposes the following product issues
- MSExchange ADAccess event 2114: Topology discovery failed, error 0x80040a02 DSC_E_NO_SUITABLE_CDC
- MSExchange ADAccess event 1601: When initializing a remote procedure call (RPC) to the Microsoft Exchange Active Directory Topology service, Exchange could not retrieve the SID for account <SID>
- MSExchange ADAccess event 2012: Domain Controller Servers in use are not responding
- MSExchange ADAccess event 2105: Exchange Active Directory Provider failed to obtain DNS records for domain <AD DNS doman name>
- MSExchange ADAccess Event 2114: Topology discovery failed, error 0x80040a02 (DSC_E_NO_SUITABLE_CDC
- MSExchangeFGPublish event 8197: Error initializing session for virtual machine <VM>. The error number is 0x80040a01
- Microsoft Exchange couldn’t read the configuration from the Active Directory directory service because of error
- Service Control Manager 7044: The following service is taking more than XX minutes to start and may have stopped responding: Microsoft Exchange System Attendant
- Service Control Manager event 7022: The Microsoft Exchange Transport service hung on starting
- Service Control Manager event 7024: The Microsoft Exchange Information Store service terminated with service-specific error 0 (0x0).
- DCPROMO demotion fails with error <don’t have dcpromoui.log | dcpromo.log> but similar to “unable to contact FAME” or “unable to contact operations master
- AD LDS replica promotion of an instance fails to source a 35 GB NTDS.DIT over the wire.
- W2K8 R2 DCPROMO promotion of the 1st DC in a child domain displays error “RPC server unavailable” with two W2K8 R2 DCs in the root domain. FFL + DFL = W2K3 in child + root domain.
- IPCONFIG /ALL with IPv6 checkbox enabled in NCPA.CPL shows ::1 as primary DNS Server IP and IPv4 address for the DNS Server in the root domain as secondary.
- UDP formatted LDAP queries + connectionless BINDS from LDP.EXE fail against W2K8 R2 domain controllers when IPv6 has been disabled in NCPA.CPL
- Portqry does not correctly report UDP 389 connectivity when IPv6 has been disabled in NCPA.CPL on W2K8 R2 domain controllers
- Unchecking the IPv6 checkbox in NCPA.CPL limits LDAP UDP queries to 2048 characters
- When either IP protocol version is disabled, the 2048 byte limit applies and the response is typically 2200 or more bytes. LDAP servers with IPv6 disabled will drop > than 2048 byte responses and the tool / caller issuing the query considers such DCs unreachable
- W2K8 R2 DCs log ADWS Instance event 1202: “This computer is now hosting the specified directory instance, but Active Directory Web Services could not service it. Active Directory Web Services will retry this operation periodically.
- W2K8 DCs stops replicating Active Directory with other W2K8 DCs in a forest that contains a mix of Windows 2003 and Windows Server 2008 DCs. While validating DNS Server IPs, the on-site PFE noticed that the IPv6 checkbox was disabled
- User logon from W7 clients joined to W2K8 R2 domains hangs for ~ 10 minutes “Applying Group Policy”
- W2K8 R2 DNS Servers randomly fail to resolve external names with error “server failure” if IPv6 checkbox is unchecked in NCPA.CPL
- W2k8 DC – Slow Client Startup because SMB2 Create and X needs 600-1600 ms, no RSS
DFS (Distributed File System)
- Users are sometimes not able to access the domain DFS namespace root \\<netbios domain>\<domain DFS root>
- Attempts by W7 clients to establish mapped drive connection to DFS shares intermittently fail with error “drive is not accessible” and see a red “X” when the drive mapping is viewed in Windows explorer. The problem may occur immediately following user logon or at any time during the day
- DFS clients received randomly DFS targets from one W2K8 R2 DC
- After disabling ipv6 Nodes cannot join the cluster