There are no known issues with ADTRAN switches and Dell workstations. Were you able to find any additional information about the nature of the failure?
The was a couple of actions taken to help normalize network connection.
Steps taken on switch:
Disabled PoS on ports supporting workstations
Enabled Edge port on all ports supporting end nodes
Disabled Power Management for Network interface http://support.microsoft.com/kb/2740020
There is still a chicken and egg situation with the new Windows 7 desktops resulting in failed initial attempts to access Domain controller or computer NETLOGON, Load Group Policies, and Time sync. These services are trying to access the DC before network is available.
“The behavior is caused by a race condition between network initialization, locating a Domain Controller and processing Group Policy. If the network is not available, a Domain Controller will not be located, and Group Policy processing will fail. Once the operating system has loaded and a network link is negotiated and established, background refresh of Group Policy will succeed.”
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