This common misperception about DNS-SD stems from the fact that the term “DNS server” is used to refer to two very different things. You can send your DNS question to any DNS server in the world, and (generally speaking) always get the same answer for your question. The answer to a DNS question depends (generally speaking) only on what the question is, not which server you ask. Just like looking up addresses, to discover services advertised in a given domain you don’t need to first configure your client to use that domain’s DNS servers. To look up the address of “you don’t need to first configure your client to use Google’s DNS servers. To look up the address of “you don’t need to first configure your client to use Amazon’s DNS servers. Or, conversely, that the client needs to be configured to use the DNS server where the service discovery records exist. It makes a lot more sense and is a lot more useful to set the domain to be one that you do have control over.Ī common misperception is that the service discovery records need to be created on a DNS server that the service discovery client is configured to use. There’s really no reason to do this, since you have no control over your ISP’s domain. In many cases people set their home gateway’s DHCP server to return their ISP’s domain name in the DHCP packet, without giving it much thought. If you don’t have have administrative access to the domain currently being returned by your DHCP server, but you do control the DHCP server, then you can change the DHCP server to return a different domain - one that you do have control over. Therefore, as long as you have administrative access to that domain’s authoritative DNS server(s), you can easily add the necessary records so the clients will discover web pages, printers, and other network services of your choosing.
When clients get a response packet from the local network’s DHCP server, there’s a domain in that packet, and clients running Mac OS X 10.4 (Tiger) or later, or iOS, or Bonjour for Windows, automatically query that domain for advertised services. One of easiest applications of Wide-Area DNS-SD is simply to add a few records to your domain’s authoritative DNS server(s), to automatically advertise selected services to clients, with zero configuration on the client side. Setting up DNS for Zero-Configuration Wide-Area Service Discovery by Clients
DNS Service Discovery is a way of using standard DNS programming interfaces, servers, and packet formats to browse the network for services.