配置 DNS 服务发现
您可以向本地设备通告单个网页，只需将五条记录添加到您的授权 DNS 服务器的区域文件即可。若要通告更多页面，每个页面还需三条记录。您必须具有区域文件的写访问权限。
【注】您不妨设定一个短的 DNS TTL（生存时间），从而不必长时间等待更新传递就可以进行测试和更改。
; 1. Domain Enumeration
; These records invite devices to browse this domain.
; (The '@' sign means "the current domain" --
; i.e. the domain being described by this zone file.)
b._dns-sd._udp IN PTR @ ; b = browse domain
lb._dns-sd._udp IN PTR @ ; lb = legacy browse domain
; (domain that will be used for devices that don’t specify a domain to browse)
; 2. List of named service entities
; These records list the named 'http' service entities you want devices
; to be able to discover. You can use upper-case, punctuation,
; UTF-8 rich text, etc., in service names, but certain punctuation
; like spaces and dots needs to be escaped with a backslash in the
; name server zone file (because that file’s content is sent as raw data, not escaped).
_http._tcp PTR New\ User\ Information\ Page._http._tcp
; 3. SRV & TXT records describing each service entity named above
; These records tell devices how to access the named 'http' service entities
; listed above. In the example below, fill in the correct host name.
; If it’s a fully qualified host name, it needs to end with a dot, as shown.
; If it’s a partial host name relative to the current zone (e.g. just "nu-info",
; with the remainder of the name being implicit) then don’t end it with a dot.
; The "path=/xxx" in the TXT record tells the web browser the specific
; page on the server it should request in its "HTTP GET" command.
; Often, but not always, the path will be just "/".
New\ User\ Information\ Page._http._tcp SRV 0 0 80 nu-info.example.com.