|
Networking device hostnames ending with .local are often employed in private networks, where they are resolved either via the multicast domain name service (mDNS) or local Domain Name System (DNS) servers. The implementation of both approaches on the same network can be problematic, however, so resolving such names via “unicast” DNS servers has fallen into disfavor as computers, printers and other devices supporting zero-configuration networking (zeroconf) have become increasingly common. ==Multicast DNS standard== Internet Engineering Task Force (IETF) standards-track RFC 6762, which has been approved and was officially published on February 20, 2013, essentially reserves the use of ''local'' as a pseudo-TLD for link-local hostnames that can be resolved via the Multicast DNS name resolution protocol.〔(【引用サイトリンク】title=RFC 6762: Multicast DNS )〕 Page 5 of that publication states: :…this document allows any computer user to elect to give their computers link-local Multicast DNS host names of the form: ''"single-dns-label.local."''. For example, a laptop computer may answer to the name ''"MyComputer.local."''… :This document specifies that the DNS top-level domain ''".local."'' is a special domain with special semantics, namely that any fully qualified name ending in ''".local."'' is link-local, and names within this domain are meaningful only on the link where they originate. This is analogous to IPv4 addresses in the 169.254/16 prefix or IPv6 addresses in the FE80::/10 prefix, which are link-local and meaningful only on the link where they originate. :Any DNS query for a name ending with the label ''".local."'' MUST be sent to the mDNS IPv4 link-local multicast address 224.0.0.251 (or its IPv6 equivalent FF02::FB)… :Implementers MAY choose to look up such names concurrently via other mechanisms (e.g., Unicast DNS) and coalesce the results in some fashion. Implementers choosing to do this should be aware of the potential for user confusion when a given name can produce different results depending on external network conditions (such as, but not limited to, which name lookup mechanism responds faster). :Name resolution issues may arise if multicast DNS software is used in conjunction with a network that implements the ''".local."'' top-level DNS domain. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「.local」の詳細全文を読む スポンサード リンク
|