Website Introduction
Www.benet.com (host name fqdn:full qualified domain name, fully qualified domainname)
There is a com,com domain below the domain that contains benet, and a host called www under the Benet domain.
Early parsing using hosts:
Configuration file/etc/hosts
IPAddr FQDN ailases
192.168.1.1 www.benet.com localhost
Hosts file disadvantages
The Hosts file needs to be filled in manually and cannot automatically get the new domain name
When the HTTP protocol began to be applied, the Internet domain name exploded, and the hosts file could not satisfy the parsing requirement.
DNS domain name resolution : Domail name Service
You can convert the FQDN to an IP address
You can also convert an IP address to an FQDN
ICANN:Maintenance of 13 root servers worldwide
Top-Level domains: Organizational domains:. com,. org,. NET,. cc
Country domain:. cn,. TW,. HK,. IQ,. IR,. JP
Second-level domain: Baidu Sina Sohu
Enquiry:
Recursion: Make a request straight
Iteration: Making multiple requests
The Internet query is two-paragraph: the client to the server request is recursive, the server query for the iteration
parsing:
Forward parsing: Fqdn<-->ip
Reverse parsing: Ip<-->fqdn
DNS Distributed Database
The superiors only know their direct subordinates.
Subordinates only know where the root is.
DNS-related types
Primary DNS server: Data modification
Secondary DNS server: Request data synchronization
Serial Number: Version
Refresh: Time period, define how long it takes to check
Retry: Retry time If the check is not reached within the specified time
Expire: Expiration time, after retrying or not checked, the primary server is considered to be hung.
Nagative Answer TTL
Cache DNS Server: not responsible for parsing, only responsible for providing authoritative answers
Forwarder: A server that forwards requests to a public network
DNS: Listening protocols and Ports
53/UDP: Client queries use
53/TCP: Synchronizing with the server
DNS record type :
SOA: Start authorization record
NS: Zone name to host name (group occurrence, one NS record and one a record)
A: Host name corresponds to IPV4 address
AAAA: Host name corresponds to IPV6 address
Ptr:ip Convert host Name
MX: Mail exchange records (need to be used with a record, MX records need to define priority)
CNAME: Alias Record
type of zone transfer:
Full zone transfer: Full transfer
Incremental zone transfer: Transfer only the changed content
Zone Type:
Primary zone: Master
From zone: Slave
Hint Area: hint
Forwarding Area: Forward
Bind Package:
Bind: Provides the main process of domain name service and related files
Bind-utils: Provides a test tool for DNS servers
Bind-libs: Provides library functions that bind and bind-utils need to use
Bind-chroot: Provides a spoofed root directory for the Bind service (Var/named/chroot folder as the root of bind) for increased security
Caching-nameserver: Provides a basic configuration file for building a cache server
Bind configuration file
/etc/named.conf Master configuration file
Cache server Configuration
options { directory "/var/named";}; zone "." IN { type hint; file "named.ca";}; zone "Localdomain" IN { type master; file "Localdomain.zone"; allow-update { none; };}; zone "0.0.127.in-addr.arpa" IN { type master; file "Named.local"; allow-update { none; };};
master server profile
" Span style= "FONT-SIZE:16PX;" > The primary server zone profile needs to have the NS record from the server
master server to add or delete records, you need to change the serial number from the server to synchronize
Options {directory "/var/named";}; Zone "." in {type hint; File "named.ca";}; Zone "benet.com" in {type Master; File "Benet.com.zone"; Allow-transfer {192.168.0.109;};}; Zone "0.168.192.in-addr.arpa" in {type Master; File "192.168.1.arpa"; Allow-transfer {192.168.0.109;};};
Primary server forward zone configuration file
$TTL 86400@ IN SOA localhost root ( 42 ; serial (d. adams) 3H ; refresh 15M ; retry 1W ; expiry 1D ) ; minimum in ns ns1.benet.com. IN NS NS2.benet.com. in mx 10 mail.benet.com.ns1 IN A 192.168.0.108ns2 IN A 192.168.0.109mail in A 192.168.0.10www in a 192.168.0.20
master server Reverse Zone profile
$TTL 86400@ IN SOA localhost root ( 42 ; serial (d. adams) 3H ; refresh 15M ; retry 1W ; expiry 1D ) ; minimum in ns ns1.benet.com. IN NS NS2.benet.com.108 IN PTR NS1.benet.com.109 IN PTR NS2.benet.com.10 IN PTR Mail.benet.com.20 in ptr www.benet.com.
From the server configuration file
Options {directory "/var/named";}; Zone "." in {type hint; File "named.ca";}; Zone "benet.com" in {type slave; File "Slaves/benet.com.zone"; Masters {192.168.0.108;};}; Zone "0.168.192.in-addr.arpa" in {type slave; File "Slaves/192.168.1.arpa"; Masters {192.168.0.108;};};
Note: If not successful, the firewall may not be turned off
Iptables-f
Setenforce 0
DNS configuration file Syntax check
Check the master configuration file for syntax errors: named-checkconf
Check the master Profile zone configuration file for syntax errors: Service named Configtest
Set power on auto start:
Chkconfig named on
Dig parsing :
Dig-t record type name (@IP specify DNS lookup)
Dig-x IP lookup for domain names based on IP
Dig +trace-t A bbs.51cto.com @222.222.222.222//tracking how to parse the
DIG-T AXFR benet.com//View all configuration files for a zone
This article from "Plum blossom fragrance from bitter cold" blog, please be sure to keep this source http://wangjunkang.blog.51cto.com/8809812/1566083
Linux Service DNS