MoinQ: DNS/RFC/8499/bailiwick

1. DNS/RFC/8499/bailiwick

について、ここに記述してください。

Bailiwick:

• "In-bailiwick" is a modifier to describe a name server
  • whose name is either a subdomain of or (rarely) the same as the origin of the zone that contains the delegation to the name server.

  In-bailiwick name servers may have glue records in their

  • parent zone (using the first of the definitions of "glue records" in the definition above). (The word "bailiwick" means the district or territory where a bailiff or policeman has jurisdiction.)
  "In-bailiwick" names are divided into two types of names for name
  • servers: "in-domain" names and "sibling domain" names.
  • In-domain: a modifier to describe a name server whose name is
    • either subordinate to or (rarely) the same as the owner name of the NS resource records.

    An in-domain name server name needs to have glue records or name resolution fails.

    • For example, a delegation for "child.example.com" may have "in-domain" name server name "ns.child.example.com".
  • Sibling domain: a name server's name that is either subordinate
    • to or (rarely) the same as the zone origin and not subordinate to or the same as the owner name of the NS resource records.

    Glue records for sibling domains are allowed, but not necessary.

    • For example, a delegation for "child.example.com" in "example.com" zone may have "sibling" name server name "ns.another.example.com".

• "Out-of-bailiwick" is the antonym of "in-bailiwick". It is a
  • modifier to describe a name server whose name is not subordinate to or the same as the zone origin. Glue records for out-of- bailiwick name servers are useless. The following table shows examples of delegation types.

   Delegation |Parent|Name Server Name  | Type
   -----------+------+------------------+-----------------------------
   com        | .    |a.gtld-servers.net|in-bailiwick / sibling domain
   net        | .    |a.gtld-servers.net|in-bailiwick / in-domain
   example.org| org  |ns.example.org    |in-bailiwick / in-domain
   example.org| org  |ns.ietf.org       |in-bailiwick / sibling domain
   example.org| org  |ns.example.com    |out-of-bailiwick
   example.jp | jp   |ns.example.jp     |in-bailiwick / in-domain
   example.jp | jp   |ns.example.ne.jp  |in-bailiwick / sibling domain
   example.jp | jp   |ns.example.com    |out-of-bailiwick