A detailed explanation of DNS service related concepts

DNS: Domain name resolution:bind:berkeleyinternet Name Domain

L

DNS: Domain Name Service

domain name:www.baidu.com(hostname,fqdn:full qualified domain name, fully qualified)

DNS: name resolution:nameresolving name translation (behind the query process, database)

FQDN---------------------------IP

Www.baidu.com 180.97.33.107

Www.163.com 218.92.220.13

Nsswitch: providing a platform

/etc/nsswitch.conf

Hosts:files DNS

File:/etc/hosts

DNS:DNS

Stub resolver: name Resolver

Ping www.baidu.com ,stub resolve first find out if there is a record in/etc/hosts, if no more DNS parsing

Hosts

IPAddr FQDN ailases

218.92.220.13 www.163.com www

Iana:ip, FQDN,

Ftp:hosts

Icann:

TLD: organization domain . com,. org,. NET,. cc

country domain . cn,. TW,. HK,. IQ,

Reverse Domain Ip-> FQDN

Reverse: Ip->fqdn

Forward Direction: Fqdn->ip

DNS Server Type

Master DNS Server: Data modification

Auxiliary DNS Server: Request data synchronization

Serial The version number of the number data file;

Refresh Check time, how long to check

Retry Retry Time

Expire Expiration Time

Negative answer TTL negative answer cache duration

Cache DNS Server

Transponder

in the database, each entry is called a resource record ( Resource Record, RR)

Format of the resource record:

TTL 600;

NAME {TTL} in RRT VALUE

Www.mylinux.com. In A 1.1.1.1

1.1.1.1 in PTR www.mylinux.com

Resource record Type:

SOA (Start of authority): This record explains how zone transfers are implemented, andSOA must be the first record in this database.

Format:

ZONE NAME TTL in SOA FQDN (

Serial number

Refresh

Retry

Expire

Na ttl)

Time Unit: M ( minutes ),H ( hours ),D ( day ),W(week)

Mailbox Format: [Email protected]- written ->admin.mylinux.com

columns:

Mylinux.com. In SOA ns1.mylinux.com. Admin.mylinux.com. (

20160707; Serial Number

1H

5M

1W

1D)

NS (name server): ZONE Name->fqdn declares itself to be a DNS server

Mylinux.com. In NS ns.mylinux.com.

Ns.mylinux.com. In A 1.1.1.1

MX (Mail eXchanger): ZONE NAME->fqdn declares itself to be a mail server,

MX ( priority:0-99, the smaller the number, the higher)

Mylinux.com. In MX ten mail.mylinux.com.

Mail.mylinux.com. In A 1.1.1.1

A (address): FQDN--IPV4

Aaa:fqdn-IPv6

PTR (pointer): FQDN with IP

CNAME (Canonical NAME): FQDN->fqdn

Www2.mylinux.com. In CNAME www.mylinux.com.

Txt

CHAOS

SRV

Domain: Domain Logic Concepts

Area: Zone Physics Concept

. com

Mylinux.com. In NS ns.mylinux.com.

Ns.mylinux.com. In A 172.16.100.0/24

Mylinux.com. 172.16.100.0/24

www 172.16.100.10

Mail 172.16.100.11,mx

Create two zone files

Forward zone files:

Mylinux.com. In SOA ns.mylinux.com. Admin.mylinux.com. (

20160707

1H

5M

1W

1D)

Www.mylinux.com. In A 172.16.100.10

can be abbreviated as :

www in A 172.16.100.10

-------------------------------------------------------

Reverse zone file:

100.16.172.in-addr.arpa.   In SOA ns.mylinux.com. Admin.mylinux.com. (

20160707

1H

5M

1W

1D)

10.100.16.172.in-addr.arpa. In PTR www.mylinux.com.

Shorthand:

Ten in PTR www.mylinux.com.

Zone Transfer Type:

Full zone transfer: AXFR

Incremental zone transfer: IXFR

Zone Type:

Primary zone: Master

From zone: Slave

Hint Area: hint

Forwarding Area: Forward

This article from "Linux operation and Maintenance" blog, declined reprint!

A detailed explanation of DNS service related concepts