I have 2 Domain Controllers with DNS and AD configuration to work as redundant, both with Windows 2003. It is an island network where I have Windows 2003 and XP clients. When I switch off the main DNS server (prefered) the secondary (alternate) doesn't resolve names for Windows 2003 clients. Works perfectly for XP clients but not W2003? Some additional configuration?

When I switch off the main DNS server (prefered) the secondary (alternate) doesn't resolve names for Windows 2003 clients. Works perfectly for XP clients but not W2003? Some additional configuration? Well, first off, 2003 is not a 'client' operating system like XP Pro....it's a 'server' OS so you shouldn't be using it as a client. If you're not and all 2003 boxes in your network are indeed servers, then they should all have statically assigned TCP/IP information (instead of using DHCP to assign their info). Make sure they all have the correct DNS addresses assigned (primary and secondary).

Thanks Curt, Actually I have no other choice than not using W2003 as a client of a Domain Server with W2003. It is an automation system and for several reasons this is required. I'm not using DHCP and yes static IPs. I still having the problem. Does anyone else have some clue?

How are you trying to resolve the names? Windows 2003 and Vista, will not use the alternate DNS server for resolving names via nslookup for example. However, it will use it for resolving names via ping. You can verify this by setting two bogus DNS servers then trying to ping google.com. This should fail and verify you aren't using cached dns for resolution. After your ping fails, leave the primary DNS as bogus and set a legitimate Alternate DNS. Ping should work. IE should also work. As you may already know, many people believe the Alternate DNS server will resolve names that the Primary can't resolve. That isn't the case. If the Primary responds, even if it can't resolve the name and responds as such, the request will fail. It will not ask the Alternate for help.

Glen, Thank you very much. Now it makes much sense to me. As you said, this seems to be related only to W2003 and Vista. And that is true. In the XP clients Alternate DNS works in that way: If primary DNS does not respond to a nslookup, the switch is made altomatically to the Alternate DNS. I left one whole day the primary switched off and I could not see any problem on resolving names for W2003 "client" stations. Ping works fine and the problem is only with the nslookup. thank you very much.