RedHat8.0 server configuration scheme (DNS)

Article Title: RedHat8.0 server configuration solution (DNS ). Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
1.1 Introduction
The most basic service in TCP/IP networks is domain name resolution. That is, you can access your website through IP address or URL. In addition, domain name resolution should also provide user naming services.
1.2 Required System Resources
Install bind-9.2.1-9 and caching-nameserver-7.2.-4. noarch. rpm
1.2.1 configuration file:
File Name and Source
/Etc/named. conf caching-nameserver-7.2.-4. noarch. rpm
/Etc/hosts system comes
/Etc/host. conf system comes
/Etc/resolv. conf system comes
/Etc/nsswitch. conf glibc-2.2.93-5
/Var/named. local caching-nameserver-7.2.-4. noarch. rpm
/Var/named. ca caching-nameserver-7.2.-4. noarch. rpm
/Var/named/name2ip. conf (/var/named/realer.com In the instance) Administrator created
/Var/named/ip2name. conf (/var/named/192.168.0 In the instance) Administrator created
1.2.2 related tools:
File Name Source
/Etc/rc. d/init. d/named bind-9.2.1-9
/Usr/bin/nslookup bind-9.2.1-9
/Usr/sbin/rndc Binary-9.2.1-9
1.3 configuration Scheme
The configuration of the DNS server involves five main files, and four other files are also related to DNS:
1./etc/named. conf configuration file
Role: defines the basic parameters and source points of the domain database information. The file can be stored locally or remotely on the server.
Instance:
$ ORIGIN realer.com.
@ In soa mail hostmaster @ realer (
# All partition files start with SOA. @ specifies the current information source. The value of realer.com can connect the domain name and named. conf. There is usually only one @ symbol.
1997022700; Serial
# Serial number
28800; Refresh
# Refresh cycle, in seconds
14400; Retry
# Cycle
3600000; Expire
# Abort time
86400); Minimum
# Time-to-live time
# The above configurations must be consistent with those in named. local.
@ In ns realer.com.
# Define a Domain Name Server
@ In mx 10 realer.com.
# Define the email server. "10" indicates the priority. The smaller the value, the higher the priority.
@ In a 192.168.0.1
Localhost in a 127.0.0.1 # map domain to IP Address
Www1 in cname www
# The two names before and after CNAME are equivalent names
Www in a 192.168.0.1
Test in a 192.168.0.2
Comp in cname test
3./var/named/192.168.0 reverse parsing File
Purpose: Implement domain name ing of IP addresses
Instance:
@ In soa gradmail.phy.pku.edu.cn.
Hostmaster@gradmail.phy.pku.edu.cn .(
1997022700; serial
28800; refresh
14400; retry
3600000; expire
86400); minimum
@ In ns realer.com.
1 in ptr realer.com.
1 in ptr www.realer.com.
1 in ptr www1.realer.com.
2 in ptr test.realer.com.
2 in ptr comp.realer.com.
# Define the inverse relationship between 192.168.0.1 and www.realer.com
Can also be used to define a reverse domain.
4./var/named. local host parsing File
Purpose: Resolve the return address localhost, Which is 127.0.0.1. The return address is a special convention that allows you to process the local address in the same way as the remote address, this simplifies the processing process and does not necessarily send data to the physical network.
Instance:
$ TTL 86400
@ In soa localhost. root. localhost .(
1997022700; Serial
28800; Refresh
14400; Retry
3600000; Expire
86400); Minimum
In ns localhost.
1 in ptr localhost.
5./var/named. ca clue File
Purpose: Initialize the buffer information. This file does not need to be changed by the administrator, but comes with the system.
6./etc/hosts
Purpose: map to other major computers on the Internet. It is usually used as a DNS backup. That is to say, the Hosts table is used when the DNS system encounters a problem.
Instance:
127.0.0.1 localhost. localdomain localhost
192.168.0.1 www.realer.com www
# Since each server has several domain names that correspond to IP addresses permanently, they should be stored in the Hosts table.
7./etc/resolv. conf
Purpose: Specify the IP address and search sequence of the Domain Name Server.
Instance:
Domain
# Define a local domain name.
Search realer.com
# Simplify the host name entered by the user, that is, when the user inputs www, the DNS can successfully resolve it to www.realer.com. It is mutually exclusive with the domain, and is used to define the search list no matter who outputs it.
Nameserver 192.168.0.1
# Define the IP address of the Domain Name Server. A maximum of three IP addresses are allowed. We recommend that you use two IP addresses.
8./etc/hosts. conf
Purpose: implement the relationship and interface between the hosts table and DNS.
Instance:
Order hosts, bind # domain name resolution order
Multi on
# Allow a computer to have multiple IP addresses
9./etc/nsswitch. conf
Role: used to process the Hosts table and DNS Sequence
Instance:
Passwd: files nisplus nis
Shadow: files nisplus nis
Group: files nisplus nis
Hosts: files dns
Bootparams: nisplus [NOTFOUND = return] files
Ethers: files
Netmasks: files
Networks: files
Protocols: files
Rpc: files
Services: files
Netgroup: nisplus
Publickey: nisplus
Automount: files nisplus
Aliases: files nisplus
1.4 test and management methods
1. The administrator needs to execute/etc/rc. d/init. d/named restart after modifying the DNS configuration file to make the change take effect.
2. rndc tool: used to send signals to the named Process
3. nslookup: test whether forward and reverse Parsing is normal.