DNS/RFC/882/日本語 - moin.dnsq.info

1. DNS/RFC/882/日本語

<<TableOfContenst()>>

提案者がどう考えていたか。

Elements of the solution

The DOMAIN NAME SPACE, which is a specification for a tree

structured name space. Conceptually, each node and leaf of the domain name space tree names a set of information, and query operations are attempts to extract specific types of information from a particular set. A query names the domain name of interest and describes the type of resource information that is desired. For example, the ARPA Internet uses some of its domain names to identify hosts; queries for address resources return ARPA Internet host addresses. However, to preserve the generality of the domain mechanism, domain names are not required to have a one-to-one correspondence with host names, host addresses, or any other type of information.

NAME SERVERS are server programs which hold information about

the domain tree's structure and set information. A name server may cache structure or set information about any part of the domain tree, but in general a particular name server has complete information about a subset of the domain space, and pointers to other name servers that can be used to lead to information from any part of the domain tree. Name servers know the parts of the domain tree for which they have complete information; these parts are called ZONEs; a name server is an AUTHORITY for these parts of the name space.

RESOLVERS are programs that extract information from name

servers in response to user requests. Resolvers must be able to access at least one name server and use that name server's information to answer a query directly, or pursue the query using referrals to other name servers. A resolver will typically be a system routine that is directly accessible to user programs; hence no protocol is necessary between the resolver and the user program.

構造化された名前空間
NAME SERVERS
RESOLVERSは名前から情報を抽出するプログラムです少なくとも1つのネームサーバにアクセスし、そのネームサーバを使用する
- 直接クエリに答えるための情報、またはクエリを追求する情報他のネームサーバーへの参照を使用します。レゾルバは典型的には、システムルーチンに直接アクセスできますユーザープログラム。したがって、レゾルバとユーザプログラム

These three components roughly correspond to the three layers or views of the domain system:

From the user's point of view,

the domain system is accessed through simple procedure or OS calls to resolvers.

The domain space consists of a single tree and the user can request information from any section of the tree.

From the resolver's point of view,

the domain system is composed of an unknown number of name servers. Each name server has one or more pieces of the whole domain tree's data, but the resolver views each of these databases as essentially static.

リゾルバの観点からは、

ドメインシステムは多数のネームサーバから構成されています。それぞれのネームサーバは全ドメインツリーのデータの一部分を担当します。ゾルバはこれらのデータベースの一部を静的に見ます。

From a name server's point of view,

the domain system consists of separate sets of local information called zones. The name server has local copies of some of the zones. The name server must periodically refresh its zones from master copies in local files or foreign name servers. The name server must concurrently process queries that arrive from resolvers using the local zones.

ネームサーバの観点からは、ドメインシステムは

ゾーンと呼ばれる個別のローカル情報セット名前サーバーには、ゾーンの一部のローカルコピーがあります。ネームサーバーそのゾーンをローカルのマスターコピーから定期的に更新する必要がありますファイルまたは外部のネームサーバ。ネームサーバーはリゾルバから到着したクエリを同時に処理するローカルゾーン。

In the interests of performance, these layers blur a bit.

For example, resolvers on the same machine as a name server may share a database and may also introduce foreign information for use in later queries. This cached information is treated differently from the authoritative data in zones.

これらのレイヤーは少しぼやけています。ために

更新または一貫性の保証

一部のユーザーは、データグラム経由でデータベースにアクセスすることを望みます。

スペースの例

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