[DominikHoffmann]

At home I have Internet access through Comcast's cable. They provide dynamic IPs through DHCP. Interestingly, as it turns out, their DHCP server doesn't provide information about what the DNS servers are. At least so it seems, because I can't use the nslookup utility from the command line nor the Lookup function in the Network Utility.

Nonetheless, domain name resolution still works, because I can type www.foxnews.com into my browser address field, and the page comes up. With no DNS known to my computer at home, how does the browser still know which Web server to query?

The reason this is relevant to me is that I would like to give one of the computers on my home network, which sits behind an Airport, a static IP address in the Airport LAN address range. The only setting that works for that computer is "Using DHCP", though. I have never gotten "Using DHCP with manual IP address" to work. I don't understand why. Perhaps this is a feature that has to be specifically supported by a DHCP server, and the Airport doesn't.

Dominik Hoffmann

[Rainy Day]

I dropped my AT&T broadband just prior to the Comcast takeover, but once had a similar setup to what you describe (and nslookup worked fine). In the Network preference panel, "DNS Servers" was left blank. At one time i had asked AT&T what the IP address of their DNS servers were, but they wouldn't give me that info. You'd think i had asked for the combination to their corporate vault. I was, however, able to figure it out eventually using nslookup (although i never had the need to use that info).

I don't understand why you're unable to do an nslookup. What do you get when you issue the command from the terminal? Have you tried nslookup while your Mac is connected directly to the cable modem with DHCP set?

I'm not familiar specifically with how Airport works, having never used it myself, but if it's like a typical broadband router, you should be able to tell Airport to talk to the cable using DHCP, and talk to Airport in any way you like (e.g. fixed IP or DHCP). You shouldn't have to enter a DNS server IP in your networking panel as Airport should pass the DNS server info along to your Mac. In other words, i suspect your problem may be in your Airport configuration.

In my current DSL setup, only my router knows the IP of my DNS servers. My Mac doesn't (but it does know the IP of the router). DNS resolves correctly for me (and nslookup works fine).