XP Clients lose WINS registrations

We have a bunch of XP machines that connect to a W2k3 SBS AD server. The server has a few static WINS bindings.

Normally this means the XP machines can go straight to "http://foo/" or whatever.

However, frequently the lookup of 'foo' results in a resolution failure on an XP client. A quick check on the server shows foo resolves just fine. On the client we must ipconfig /registerdns and we have to do this sometimes several times a day. The clients can continue to ping the AD server without loss.

All the XP machines are affected. Any clues what might be causing this? The only diagnostics I have read about so far are to interrogate the AD server - which is operating just fine.

I'm a bit lost in your question. You talk about WINS but then you bring "ipconfig /registerdns" into it. "ipconfig /registerdns" on a client won't do anything to affect the client's ability to resolve NetBIOS names.

I don't think you're actually solving your problem with the "ipconfig /registerdns" (especially because you say you have to do it several times a day). I suspect you're getting a bit of a placebo effect from running this.

The Right Thing^TM to do, to me, would be to sniff the name resolution traffic coming out of a client when it can't resolve the "foo" name and see what it's trying to do. W/ Windows XP clients I would expect to see it querying its primary DNS server for "foo.primary.DNS.suffix" first, followed by all the suffixes in the "DNS Suffix Search List" (run "ipconfig /all" on the client to see this list). If it doesn't get back a satisfactory answer from DNS then it'll fall back to NetBIOS name resolution. You should see a request sent to its WINS server and then, assuming you're using "H-node" NetBIOS name resolution, a broadcast for the name.