In the school I work in we have a large number (500+) of Windows 7 laptops on a Meru Wireless system and Server 2008 R2 Servers. We have an appalingly large failure rate where a student or staff member tries to logon (to the laptop joined to the domain) and is met by "There are currently no logon servers available to service the logon request". I've seen this question and this one and while removing and re-joining to the domain works, it's highly time consuming, irritating, and we (I) have more important things to concentrate on. The only MS KB article I can find is regarding a read-only domain controller (which ours isn't) and I'm at my wits end.
Ultimately, is there a definitve cause and answer to this or am I stuck removing and re-joining the laptops?
Best Answer
I'm making some assumptions. Tell me if I'm wrong. I'm assuming these clients are obtaining IP addresses from DHCP and are only receiving, as DHCP options, the addresses of DNS servers running on Active Directory domain controller computers. If they aren't then I'd start by making these assumptions true first.
In my opinion you'd do well to use a sniffer to examine the traffic between the client computer and the domain controller(s) to determine what's actually happening behind the scenes. That should give you an idea of where to begin to focus your efforts.
By the user logon stage of the boot process you should be seeing the client making DNS requests to locate DC's, followed by LDAP and SMB/CIFS requests to determine site membership, apply machine group policy, etc.
In the case of an all wireless network I'd wonder if you're seeing sufficient packet loss as to make DNS unreliable, which will cause the rest of the logon process to fail. If you haven't isolated the wireless network from the equation yet I'd recommend attaching an affected computer to a wired network, booting it up from a powered-off state, allowing it to pull DHCP (and, ideally, watching either in your DHCP server's management interface or a sniffer to see that it actually pulls an IP address), and see if it acts differently. If it does then that's a sign that your wireless network may be the culprit.
It's not magic. Watch the packets on the wire-- they're trying to tell you what's going on.