I've been bothered by this for a little while now. I reboot my laptop, it connects to my router (WLAN), gets its address (as well as the DNS server's address) via DHCP. But the machine cannot resolve any names. Vista reports my LAN is "local only". Diagnostics say the DNS is not working. I used Wireshark, and discovered that when I try to resolve a name, such as when I type "ping www.google.com" at the command prompt, it sends all resolution requests to my WINS server, which of course says it has no address for it, but does not, when that fails, attempt to resolve through the DNS. Wireshark showed no traffic on port 53 at all.
I ran NSLookup, which reports my router IP Address as the DNS. IPCONFIG /all shows my wireless connection has my router's IP as the DNS server. But Wireshark shows NO traffic on port 53 going to/from the router. What's up with that?
Eventually, many long minutes later, I don't know exactly how long I waited, it starts working... I have no idea why.
That is, I had no idea until today. I think I have figured this out. I have a gigabit ethernet port on my laptop as well, which IPConfig correctly reports as "Media disconnected". But, now I notice in Wireshark, when you list all the interfaces, my gigabit ethernet port is listed, with an IP Address defined! I had recently plugged my computer into my router with a cable, to move some large files I wanted to move faster. So this IP Address I see assigned to my "media disconnected" port is, of course, on the same subnet as my wireless connection. Hmmmmm. If Wireshark thinks there is a gigabit port with an address on my subnet, maybe Vista does too? Maybe it's trying to reach the DNS on this faster, all but disconnected, interface?
So I went to Control Panel/Network Connections, and disabled my gigabit port. Interesting, the DNS issue was immediately resolved. I rebooted, and as soon as I got an address on my wireless WLAN, it immediately says it is enabled for local and internet. Now I'm blogging about it. So if the problem is not permanently resolved, I'll have to update this post.
So I think I've solved the problem. And perhaps I've discovered a bad bug in Vista (I have all current service packs and updates installed). It appears to me, anecdotally at least, that that when the ethernet port gets an address assigned, but then gets disconnected (but is still enabled), it may have some effect on your networking.
Note that I do have a WINS server hardcoded for my WLAN connection. And it is NOT on my local subnet at home. But it is routable (my home router has a site-to-site VPN with the office) so the WINS server was responding to the requests. I only mention this because in other posts I found while researching this, at least one had posted an IPCONFIG /ALL result which showed something similar - the DNS was defined (as the router's address) and there was a WINS server defined as well, but on another subnet, but the DNS was not being accessed properly. Relevant? I have no idea.
I hope someone finds this information useful...