DNS の仕組みの基本を理解しよう - 明星大学

1 DNS 1 DNS DNS DNS DNS DNS IP IP DNS IP hosts Linux /etc/hosts Windows 2000 Windows \system32\drivers\etc localhost host1 gw www 1 hosts hosts ARPANET hosts ARPANET DNS 1984 hosts DNS DNS hosts 1 1 DNS DNS DNS.

2 1 2 Name Space DNS IP DNS DNS DNS DNS DNS DNS jp DNS jp DNS co DNS co DNS DNS IP DNS DNS host1 1 DNS 1 FQDN Fully Qualified Domain Name FQDN www FQDN.

3 Web FQDN FQDN DNS 3 DNS 1 DNS DNS delegation DNS DNS 2 4 DNS 2 DNS DNS DNS DNS DNS 1 DNS 1 DNS 1 DNS 1 1 1 DNS 1 1 IP 1 SOA Start Of a zone Of Authority DNS DNS 3 NS DNS DNS A IP Web URL IP DNS A

4 A IP DNS IP PTR DNS 5 SOA DNS 3 refresh retry expire TTL NS DNS A IP PTR IP CNAME MX HINFO OS WKS Well Known Services TXT 1 DNS 6 Web IP PTR MX sendmail MTA DNS MX 3 MX MX DNS DNS DNS DNS 7 IP jp DNS DNS jp DNS IP jp DNS 1 TLD Top Level Domain DNS DNS DNS.

5 Com .net .jp DNS DNS DNS 4 DNS DNS 4 DNS 8 4 DNS DNS DNS DNS DNS DNS DNS DNS Recursive DNS DNS Iterative

6 DNS DNS Full-Service Resolver DNS PC Stub Resolver DNS Slave Server DNS DNS DNS PC DNS DNS DNS 9 SOA A MX PTR PTR IP 5 DNS.

7 DNS 10 IP IP 1 DNS 2 DNS .. DNS DNS IP CIDR Classless Inter-Domain Routing IANA DNS CIDR IP DNS IP 11 DNS 2 DNS DNS FQDN DNS 1 TLD Top Level Domain SLD Second Level Domain TLD ICANN Internet Corporation for Assigned Names and Numbers IP ICANN

8 2 1 gTLD generic TLD 7 1 ccTLD country code TLD TLD ccTLD ISO-3166 JIS X 0304 12 TLD gTLD .com ICANN VGRS .net ICANN VGRS .org ICANN VGRS .edu 4 2 Educause .gov General Services Administration .mil DoD Network Information Center .int IANA ccTLD .jp .kr JPNIC JPRS 1 TLD gTLD .com .net .org ICANN .edu .mil .gov gTLD .gov 2000 ICANN 7 gTLD 5 gTLD 13 TLD.

9 Biz .com NeuLevel .info Afilias Limited .name SLD Global Name Registry .museum SLD Museum Domain Management Association .coop NCBA National Cooperative Business Association .aero SITA Societe Internationale de Telecommunications Aeronautiques SC .pro RegistryPro 2 gTLD ICANN gTLD ICANN gTLD TLD cyber squatting 14 IP gTLD DNS gTLD ccTLD NIC Network Information Center JPNIC ( )

10 SLD jp SLD co ne go SLD co au com SLD SLD ac 4 co go ad JPNIC ne ISP or gr ed SLD . 3 jp SLD 15 DNS 3 DNS DNS DNS DNS DNS DNS DNS DNS DNS 1 DNS 16 DNS 2 DNS DNS DNS DNS 1 1