DNS服务器基本服务（正向、反向解析）、别名、递归、迭代、增量传输、完全传输

1.基础了解

DNS服务：

FQDN:完全符合规格的域名

正向解析:FQDN---->IP

反向解析:IP----->FQDN

DNS查询类型：

递归查询

迭代查询

DNS服务类型：

主从

缓存

指定DNS服务器：

/etc/resolv.conf

本地DNS解析：

/etc/hosts

2.提供基本DNS服务解析

2.1正向解析（环境为cenos6.8）

2.1.1.服务前安装软件：bind.x86_64 bind-libs-9.8.2-0.47.rc1.el6_8.1.x86_64 bind-utils-9.8.2-0.47.rc1.el6_8.1.x86_64

2.1.2.配置正向解析文件

2.1.2.1主配置文件：在/etc/named.conf里面

listen-on port 53 { any; };DNS服务监听端口

directory "/var/named";定义配置文件目录

allow-query { any; };允许DNS查询的ip地址或者ip地址范围

recursion yes;允许递归查询

include "/etc/named.rfc1912.zones";包含zone的配置文件

DNS服务器基本服务（正向、反向解析）、别名、递归、迭代、增量传输、完全传输

2.1.2.2.主区域配置文件：在/etc/named.rfc1912.zones下

zone "uplooking.com" IN { 定义区域名

type master;制定区域类型{master,slave,hint,forward}

file "uplooking.com";制定区域文件名

};

2.1.2.3.区域文件配置：在/var/named/新建一个up14.com

修改权限：chown root.nomed up14.com

编辑up14.com 内容为以下：

$TTL 1D

@ IN SOA ns.uplooking.com. admin.uplooking.com. (

0 ; serial

1D ; refresh

1H ; retry

1W ; expire

3H ) ; minimum

uplooking.com. IN NS ns.uplooking.com.

ns.uplooking.com. IN A 172.16.10.1

www IN A 172.16.10.1

bbs IN A 172.16.10.1

IN MX 10 mail

mail IN A 172.16.10.1

bbs2 IN CNAME bbs

2.1.2.4。重启服务：

/etc/init.d/named restart 重启named服务

named-chekconf 检查named.conf

named-chekzone "up14.com" /var/named/up14.com 检查/var/named/up14.com文件

2.1.2.5.编辑/etc/resolv.conf指定服务器IP地址（本次试验机为192.168.119.128）

例：; generated by /sbin/dhclient-script
#search localdomain （#表示将原来得注释掉）
#nameserver 192.168.119.2 （#表示将原来得注释掉）
nameserver 192.168.119.128 （新增加）

2.1.2.6.解析检查：dig -t A www.up14.com或者nslookup www.uplooking.com

例：[root@localhost etc]# dig -t A www.up14.com

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.47.rc1.el6_8.1 <<>> -t A www.up14.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 64037
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;www.up14.com. IN A

;; ANSWER SECTION:
www.up14.com. 86400 IN A 192.168.119.128

;; AUTHORITY SECTION:
up14.com. 86400 IN NS ns.up14.com.

;; ADDITIONAL SECTION:
ns.up14.com. 86400 IN A 192.168.119.128

;; Query time: 1 msec
;; SERVER: 192.168.119.128#53(192.168.119.128)
;; WHEN: Sat Oct 8 21:36:36 2016
;; MSG SIZE rcvd: 79

解析成功！

2.2.反向解析
2.2.1主区域文件配置在/etc/named.rfc1912.zones里面

格式：

zone "100.168.192.in-addr.arpa" IN {

type master;

file "192.168.100.zone";

};

2.2.2区域配置文件在/var/named/里面新建一个192.168.100.zone文件

输入格式

$TTL 600

@ IN SOA ns1.up14.com. admin.up14.com. (

20140904

)

IN NS ns1.up14.com.

200 IN PTR ns1.up14.com.

221 IN PTR www.up14.com.

222 IN PTR www.up14.com.

2.2.3.重启服务：

/etc/init.d/named restart 重启named服务

named-chekconf 检查named.conf

named-chekzone "100.168.192.in-addr.arpa" /var/named/192.168.100.zone 检查/var/named/up14.com文件

2.2.4.编辑/etc/resolv.conf指定服务器IP地址（本次试验机为192.168.100.128）

例：; generated by /sbin/dhclient-script
#search localdomain （#表示将原来得注释掉）
#nameserver 192.168.119.2 （#表示将原来得注释掉）

nameserver 192.168.119.128 （新增加正向解析IP---> 此步为上面正向解析保留得IP地址可以不要)
nameserver 192.168.100.128 （新增加反向解析IP)

2.2.5.验证反向解析：dig -x 192.168.100.221

例：[root@localhost named]# dig -x 192.168.100.221

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.47.rc1.el6_8.1 <<>> -x 192.168.100.221
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51833
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;221.100.168.192.in-addr.arpa. IN PTR

;; ANSWER SECTION:
221.100.168.192.in-addr.arpa. 600 IN PTR www.up14.com.

;; AUTHORITY SECTION:
100.168.192.in-addr.arpa. 600 IN NS ns1.up14.com.

;; Query time: 0 msec
;; SERVER: 192.168.119.128#53(192.168.119.128)
;; WHEN: Sat Oct 8 21:58:43 2016
;; MSG SIZE rcvd: 90

解析成功！

3.增加DNS别名
在zone文件中添加以下内容实现别名

bbs2 IN CNAME bbs

4.泛域名解析：

* IN A 192.168.119.128 或者 *.uplooking.com. IN A 192.168.119.128

5.递归和迭代解析流程

5.1 迭代

dig +norecurse -t A www.sohu.com @192.168.119.128