Domain Name System (for Linux)

Presentasi berjudul: "Domain Name System (for Linux)"— Transcript presentasi:

1 Domain Name System (for Linux)

2 Apa itu DNS? Sebuah protokol layer 7 yang berisi database records (domain +ip) yang bertugas memappingkan ip dengan hostname (domain name) yang diminta client.

3 DNS Host di Internet menggunakan alamat IP sebagai identitas
ex: Numeric ID tidak human friendly Alphanumeric lebih mudah diingat

4 Mengapa perlu DNS? Perlu skema pemetaan antara IP dengan nama
Pada awalnya menggunakan file

5 Hosts file tidak praktis
Network berkembang, makin sulit update database Solusi: menggunakan DNS RFC 1034 dan 1035 Port 53

6 Primary Purpose Resolve hostnames to IP addresses
 Resolve IP addresses to hostnames 

7 Cara kerja DNS Hirarki proses Database distribution

8 Terminologi Terms Domain – a collection of records with a contiguous namespace mydomain.com Subdomain – a collection of records with a contiguous namespace that are hierarchically beneath another domain newyork.mydomain.com cincinnati.mydomain.com Zone – a collection of records that comprise a DNS domain Name Server or DNS Server A server capable of either answering queries for records it owns or answering queries on behalf of DNS clients, or both.

9 Terminologi lanjutan Terms (continued)
Record – either a forward or reverse name mapping “A” Record – Maps hostname to IP Address  “CNAME” Record – Maps an alias to a hostname  redmond.jeffneddie.com. PTR Record – Maps an IP address to a hostname  redmond.jeffneddie.com. MX Record – Defines a mail exchanger for a host or domain MX  mymailserver.mydomain.com. SOA Record – Start of Authority – contains a list of authoritative name servers, TTL values, etc. SOA  mydomain.com. NS Record – Lists authoritative name servers for a domain NS  mydnsserver.mydomain.com. SRV Record – Maps a service to a hostname LDAP  mydc.mydomain.com.

10 Root DNS Server edu DNS Server Org DNS Server Com DNS Server

11 DNS name space Top Level Domain Second Level Domain
Generic (com, edu, net, biz, org dll) Country code ( id, au, my, jp, sg dll) Second Level Domain

12 DNS name space Second level domain: co.id ac.id or.id Dll

13 Server dan client Name server Resolver (client)
Menyimpan/mengatur domain name Melayani permintaan dari client Resolver (client)

14 Resolver Client part of DNS Trigger DNS query Bagian dari OS

15

16 Name Server Authoritative DNS Server
DNS Server Organisasi, melayani mapping hostname ke IP yang ada di org tsb Di kelola oleh org tsb atau ISP

17 Name Server Local Name Server Dimiliki oleh setiap ISP
Default name server Jika sebuah host memilik DNS query, query tsb dikirim ke name server lokal

18 DNS Name Resolution Iterative (request perulangan sampai kondisi terpenuhi) Recursive (request sekali, yang penting kondisi terpenuhi)

19 Iterative

20 Recursive Request it.intel.com Root name server Name server for .com
client name server for intel.com name server for it.intel.com