DNS
DNS namespace
fully qualified domain name (FQDN) Hostname Domain Top level Acct. Dir. PC adatum com Fully qualified domain name = Acct. Dir. PC. adatum. com
DNS zone – часть от DNS пространства имен, которая содержит DNS записи Типы DNS Zone : • Forward lookup zone • Reverse lookup zone fqdn -> ip ip -> fqdn Ресурсные записи forward lookup zones: • A, - fqdn=ipv 4 • AAAA – fqdn=ipv 6 • CNAME, MX, SRV, NS, SOA Ресурсные записи в reverse lookup zones: • PTR – ipv 4=fqdn
DNS Names Resolving в Internet. root DNS Какой IP address у www. microsoft. com? 2 3 1 Workstation . com DNS Local DNS Server 4 207. 46. 230. 219 у www. microsoft. com 5 Microsoft. com DNS
Что используется и в какой последовательности используется для Resolving LMHosts File 8 Broadcast 1 7 2 6 WINS Server Local Host Name DNS Resolver Cache/Hosts file content 3 5 Net. BIOS Name Cache 4 LLMNR DNS Server
DNS recurcive query, DNS iterative query recursive запрос отправился к DNS server и он отправил ответ на запрос mail 1. contoso. com 172. 16. 64. 11 DNS client Local DNS server
DNS query Client Recursive query mail 1. contoso. com 172. 16. 64. 11 Iterative query Ask. com Iterative query Ask contoso. com Local DNS server Root hint (. ) Iterative query Authoritative response . com contoso. com
Root Hints Root hints содержит IP адреса for DNS root серверов Root (. ) Servers DNS Servers Root Hints com DNS Server Client microsoft
Forwarder A forwarder is a DNS server назначенный для отправки resolving запросов external or offsite DNS domain names Client Recursive query mail 1. contoso. com 131. 107. 0. 11 Iterative query Root hint (. ) Ask. com Recursive query Iterative query Ask contoso. com 131. 107. 0. 11 Local DNS server Iterative query Authoritative response Forwarder . com contoso. com
Conditional Forwarder Conditional forwarding пересылает запросы используя условия на сервер имени домена All Other DNS Domains Query for www. contoso. com Local DNS server ISP DNS contoso. com Client contoso. com DNS
DNS Server Caching DNS server cache Host name IP address TTL Server. A. contoso. com 131. 107. 0. 44 28 seconds Where is Server. Ais at Server. A? 131. 107. 0. 44 Client 1 Server. Ais at Where is 131. 107. 0. 44 Server. A? Client 2 Server. A
Типы DNS Zones Description Primary Read/write copy of a DNS database Secondary Read-only copy of a DNS database Stub Copy of a zone that contains only records used to locate name servers Active Directoryintegrated Zone data is stored in AD DS rather than in zone files