Hi,

Here's my setup

1 x Windows Server 2008 R2 Enterprise SP1 with the Hyper-V server Role installed. This is in a workgroup.

3 x Windows Server 2008 R2 Standard SP1 Guest VM's on the above host. These are all members of a domain.

The security log on the Hyper-V server is registering this failed logon event from all three of the servers every few minutes. See below for an example (Replacements are shown in square brackets):

"An account failed to log on.

Subject:
Security ID: NULL SID
Account Name: -
Account Domain: -
Logon ID: 0x0

Logon Type: 3

Account For Which Logon Failed:
Security ID: NULL SID
Account Name: <COMPUTER_NAME>$
Account Domain: <DOMAIN_NAME>

Failure Information:
Failure Reason: Unknown user name or bad password.
Status: 0xc000006d
Sub Status: 0xc0000064

Process Information:
Caller Process ID: 0x0
Caller Process Name: -

Network Information:
Workstation Name: <GUEST_VM_NAME>
Source Network Address: fe80::1c28:2c67:af3f:407c
Source Port: 52039

Detailed Authentication Information:
Logon Process: NtLmSsp 
Authentication Package: NTLM
Transited Services: -
Package Name (NTLM only): -
Key Length: 0

This event is generated when a logon request fails. It is generated on the computer where access was attempted.

The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe.

The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network).

The Process Information fields indicate which account and process on the system requested the logon.

The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases.

The authentication information fields provide detailed information about this specific logon request.
- Transited services indicate which intermediate services have participated in this logon request.
- Package name indicates which sub-protocol was used among the NTLM protocols.
- Key length indicates the length of the generated session key. This will be 0 if no session key was requested."

I've tried running process monitor to see what network traffic is going from each guest to the host but the only traffic I can see is Link Local Name resolution traffic. Could this be the problem? If so, how do I stop these logon failures from occurring?

Thanks in advance

Greg