DNS服务器架设

 这篇文档，是我根据一个视频教程作出来的笔记，上传的PDF则为这个视频的课件，想看看见不想看我这个的，可以下载就是了，但下面所写，均为我个人测试所得，有什么问题，尽管可以回帖

DNS概述
DNS安装
DNS常见名词
DNS配置文件详解
配置主要DNS服务
DNS案例详解

DNS域名系统简介
 
四部分组成
    DNS域名空间
    资源记录
    DNS服务器
    DNS客户端
DNS域名空间
根域-->顶极域-->子域-->主机
分成三个类型
    组织域--地址域--反向域

DNS查询工作的原理
两部分组成
    本地解析
    查询DNS服务器
        递归查询    (服务器与服务器交流)
        迭代查询(流量会增大，服务器与客户端的交流)
hosts文件
/etc/hosts解析网络中的IP地址跟域名

DNS服务器bind及chroot的安装
比较注意的一个caching-nameserver很多文件已经配置好，比较方便，故此，需要装上
rpm -q bind查询是否安装

yum -y install bind-*
yum -y install caching-nameserver-*

rpm -ql caching-nameserver

/var/name/named.ca根服务器的配置文件

安装chroot软件包
原因

优点
危害减少

启动/停止/重启 DNS

DNS常见名词
区
资源记录
区文件
DNS缓存
正向解析
反向解析

DNS配置文件详解
/etc/named.conf
/var/named/named.ca
/var/named/localhost.zone
/var/named/name.local
/var/named/


资源记录
SOA资源记录

主配置文件named.conf
options{
directory "/var/named"; 指定工作目录
forwards {192.168.31.2} 指定查询的目标DNS服务器
allow-transfer   -->辅助DNS的时候用到


};


type字段指定的区域类型
master:定义的是主域名服务器
slave:辅助域名服务器
hint:互联网中根域服务器
forward:
stub:
delegation-only

DNS服务器架设流程
    建立named.conf
    建立区域文件
    重新加载配置文件使配置生效


配置主要名称服务器的概述
主配置文件
主配置文件
/etc/named.conf

设置根区域
zone "."{
    type hint;
   
};
设置主区域
zone "example.com"{
    type master;
   

};
设置反向解析区域
zone "16.168.192.in-addr.arpa"{
    type master;
    file "192.168.16.arpa";
};
根服务器信息文件named.ca
ftp下载复制到/var/named/chroot/var/named/目录下



正向区域文件



反向解析区域文件
/var/named/chroot/var/named/192.168.16.arpa

实现负载均衡功能


主要名称服务器的测试
1 测试前的准备
启动DNS服务

配置/etc/resolv.conf

2 使用nslookup程序测试

3 host [-t type] hostname [server][ip]
4 dig [-t type] hostname [server][ip]

最简单的服务器配置
host 51CTO提醒您，请勿滥发广告!
发现，超时

cd /var/named/chroot/
cd etc;ls
建立named.conf文件
options {
    directory "/var/named";

};
zone "."{
    type hint;
    file "named.ca"
};


ls -l named.conf
默认是root用户组
host 51CTO提醒您，请勿滥发广告!

如果没有安装chroot的包的话，比需要把文件的权限更改掉
host ip
dig 51CTO提醒您，请勿滥发广告!

nslookup 51CTO提醒您，请勿滥发广告!


named-checkconf 检查区域文件
named-checkconf named.conf检查

named-checkconf named.ca /var/named/chroot/var/named/named.ca

配置辅助名称服务器
优点
    提供容错能力
    分担主服务器的负担
    加快查询的速度
/etc/named.conf

配置缓存cache-only服务器
类似于代理服务器
options{
dirc
forward only;
forwarders{
    ip;
};
};


案例
实例1】技术部所在域为“tech.org”，部门内有三台主机，主机名分别是 client1.tech.org,client2.tech.org,client3.tech.org。现要求DNS服务器dns.tech.org 可以解析3台主机名和IP地址的对应关系。

[root@localhost etc]# yum -y install bind-*
[root@localhost etc]# yum -y install caching-nameserver-*

[root@localhost /]# cd /var/named/chroot/etc/
[root@localhost etc]# ls
localtime  named.caching-nameserver.conf  named.rfc1912.zones  rndc.key
[root@localhost etc]# vim named.conf
options{
        directory "/var/named";
};
zone "."{
        type hint;
        file "named.ca"

};
zone "tech.org"{
        type master;
        file "tech.org.zone";


};
zone "141.16.172.in-addr.arpa"{
        type master;
        file "172.16.141.zone";
};
~           
建立区域文件
[root@localhost etc]# cd ..
[root@localhost chroot]# ls
dev  etc  var
[root@localhost chroot]# cd var/named/
[root@localhost named]# ls
data              localhost.zone   named.ca         named.local  slaves
localdomain.zone  named.broadcast  named.ip6.local  named.zero
[root@localhost named]# vim tech.org.zone

$TTL 86400
@       IN              SOA             dns.tech.org.   root(
                                        2011071300
                                        3H
                                        1H
                                        0)
@       IN              NS              dns.tech.org.
dns     IN              A               172.16.141.132
client1 IN              A               172.16.141.133
client2 IN              A               172.16.141.134
client3 IN              A               172.16.141.135

建立反向区域
[root@localhost named]# vim 172.16.141.zone

$TTL 86400
@               IN              SOA             dns.tech.org.   root.tech.org. (
                                                2011071300
                                                3H
                                                1H
                                                1W
                                                0)
@                           IN              NS      dns.tech.org.
132.141.16.172.in-addr.arpa.            IN              PTR     dns.tech.org.
133                                     IN              PTR     client1.tech.org.
134                                     IN              PTR     client2.tech.org.      
135                                     IN              PTR     client3.tech.org.      
~                                                                                    
检查区域文件
[root@localhost named]# named-checkzone tech.org.zone /var/named/chroot/var/named/tech.org.zone
zone tech.org.zone/IN: loaded serial 2011071300
OK

[root@localhost named]# named-checkzone 172.16.141.zone /var/named/chroot/var/named/172.16.141.zone
/var/named/chroot/var/named/172.16.141.zone:9: ignoring out-of-zone data (132.141.16.172.in-addr.arpa)
zone 172.16.141.zone/IN: loaded serial 2011071300
OK
[root@localhost named]#



[root@localhost named]# service named start
Starting named:                                            [  OK  ]

[root@localhost named]# dig -t PTR 133.141.16.172.in-addr.arpa

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> -t PTR 133.141.16.172.in-addr.arpa
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39593
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

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

;; ANSWER SECTION:
133.141.16.172.in-addr.arpa. 86400 IN   PTR     client1.tech.org.

;; AUTHORITY SECTION:
141.16.172.in-addr.arpa. 86400  IN      NS      dns.tech.org.

;; ADDITIONAL SECTION:
dns.tech.org.           86400   IN      A       172.16.141.132

;; Query time: 1 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Wed Jul 13 16:21:15 2011
;; MSG SIZE  rcvd: 109

[root@localhost named]#


实例2】企业采用多个区域管理各部门网络，技术部属于“tech.boobooke”域，市场部属于“mart.boobooke”域，其他人员属于“freedom.boobooke”域。
技术部门共有100人，采用的IP地址为192.168.31.1-192.168.31.100。
市场部门共有100人，采用IP地址为192.168.32.1-192.168.32.100。
其他人员只有50人，采用IP地址为192.168.33.1-192.168.33.50。
现采用一台主机搭建DNS服务器，其IP地址为192.168.31.134，要求这台DNS服务器可以完成内网所有区域的正/反向解析，
并且所有员工均可以访问外网地址。

配置named.conf
options{
        directory "/var/named";
};
zone "."{
        type hint;
        file "named.ca";

};
zone "tech.boobooke"{
        type master;
        file "tech.boobooke.zone";


};
zone "141.16.172.in-addr.arpa"{
        type master;
        file "172.16.141.zone";
};


zone "mark.boobooke"{
        type master;
        file "mark.boobooke.zone";


};
zone "142.16.172.in-addr.arpa"{
        type master;
        file "172.16.142.zone";
};
zone "freedom.boobooke"{
        type master;
        file "freedom.boobooke.zone";


};
zone "143.16.172.in-addr.arpa"{
        type master;
        file "172.16.143.zone";
};


                                                                                                                                                        
[root@localhost named]# mv tech.org.zone tech.boobooke.zone
[root@localhost named]# cp tech.boobooke.zone mark.boobooke.zone
[root@localhost named]# cp tech.boobooke.zone freedom.boobooke.zone
[root@localhost named]# cp 172.16.141.zone 172.16.142.zone
[root@localhost named]# cp 172.16.141.zone 172.16.143.zone

[root@localhost named]# vim tech.boobooke.zone

$TTL 86400
@       IN              SOA             dns.tech.boobooke.      root (
                                        2011071300
                                        3H
                                        1H
                                        1W
                                        0)
@       IN              NS              dns.tech.boobooke.
dns     IN              A               172.16.141.132
client1 IN              A               172.16.141.1
client2 IN              A               172.16.141.2
client3 IN              A               172.16.141.3
client100 IN            A               172.16.141.100

[root@localhost named]# vim mark.boobooke.zone

$TTL 86400
@       IN              SOA             dns.mark.boobooke.      root (
                                        2011071300
                                        3H
                                        1H
                                        1W
                                        0)
@       IN              NS              dns.mark.boobooke.
dns     IN              A               172.16.141.132
client1 IN              A               172.16.142.1
client2 IN              A               172.16.142.2
client3 IN              A               172.16.142.3
client100 IN            A               172.16.142.100

[root@localhost named]# vim freedom.boobooke.zone

$TTL 86400
@       IN              SOA             dns.freedom.boobooke.   root (
                                        2011071300
                                        3H
                                        1H
                                        1W
                                        0)
@       IN              NS              dns.freedom.boobooke.
dns     IN              A               172.16.141.132
client1 IN              A               172.16.143.1
client2 IN              A               172.16.143.2
client3 IN              A               172.16.143.3
client50 IN            A               172.16.143.50

然后编辑反向区域
[root@localhost named]# vim 172.16.141.zone

$TTL 86400
@               IN              SOA             dns.tech.boobooke.      root.tech.boobooke. (
                                                2011071300
                                                3H
                                                1H
                                                1W
                                                0)
@               IN              NS              dns.tech.boobooke.
132             IN              PTR     dns.tech.boobooke.
1                               IN              PTR     client1.tech.boobooke. 
2                               IN              PTR     client2.tech.boobooke. 
3                               IN              PTR     client3.tech.boobooke. 
100                             IN              PTR     client100.tech.boobooke.


 [root@localhost named]# cp 172.16.141.zone 172.16.142.zone
cp: overwrite `172.16.142.zone'? y
[root@localhost named]# cp 172.16.141.zone 172.16.143.zone
cp: overwrite `172.16.143.zone'? y
[root@localhost named]# vim 172.16.142.zone
 $TTL 86400
@               IN              SOA             dns.mark.boobooke.      root.mark.boobooke. (
                                                2011071300
                                                3H
                                                1H
                                                1W
                                                0)
@               IN              NS              dns.mark.boobooke.
132             IN              PTR     dns.mark.boobooke.
1                               IN              PTR     client1.mark.boobooke.
2                               IN              PTR     client2.mark.boobooke.
3                               IN              PTR     client3.mark.boobooke.
100                             IN              PTR     client100.mark.boobooke.

[root@localhost named]# vim 172.16.143.zone

$TTL 86400
@               IN              SOA             dns.freedom.boobooke.   root.freedom.boobooke. (
                                                2011071300
                                                3H
                                                1H
                                                1W
                                                0)
@               IN              NS              dns.freedom.boobooke.
132             IN              PTR     dns.freedom.boobooke.
1                               IN              PTR     client1.freedom.boobooke.
2                               IN              PTR     client2.freedom.boobooke.
3                               IN              PTR     client3.freedom.boobooke.
50                              IN              PTR     client50.freedom.boobooke.


[root@localhost named]# named-checkconf /var/named/chroot/etc/named.conf
[root@localhost named]# named-checkzone 172.16.141.zone /var/named/chroot/var/named/172.16.141.zone
zone 172.16.141.zone/IN: loaded serial 2011071300
OK
[root@localhost named]# named-checkzone 172.16.142.zone /var/named/chroot/var/named/172.16.142.zone
zone 172.16.142.zone/IN: loaded serial 2011071300
OK
[root@localhost named]# named-checkzone 172.16.143.zone /var/named/chroot/var/named/172.16.143.zone
zone 172.16.143.zone/IN: loaded serial 2011071300
OK
[root@localhost named]# named-checkzone tech.boobooke.zone /var/named/chroot/var/named/tech.boobooke.zone
zone tech.boobooke.zone/IN: loaded serial 2011071300
OK
[root@localhost named]# named-checkzone mark.boobooke.zone /var/named/chroot/var/named/mart.boobooke.zone
zone mart.boobooke.zone/IN: loaded serial 2011071300
OK
[root@localhost named]# named-checkzone freedom.boobooke.zone /var/named/chroot/var/named/freedom.boobooke.zone
zone freedom.boobooke.zone/IN: loaded serial 2011071300
OK

[root@localhost named]# service named restart
Stopping named:                                            [  OK  ]
Starting named:                                            [  OK  ]
[root@localhost named]#

[root@localhost named]# host client1.tech.boobooke
client1.tech.boobooke has address 172.16.141.1
[root@localhost named]# host client1.mark.boobooke
client1.mark.boobooke has address 172.16.142.1
[root@localhost named]# host client1.freedom.boobooke
client1.freedom.boobooke has address 172.16.143.1
[root@localhost named]#
[root@localhost named]# host 172.16.141.100
100.141.16.172.in-addr.arpa domain name pointer client100.tech.boobooke.
[root@localhost named]# host 172.16.142.100
100.142.16.172.in-addr.arpa domain name pointer client100.mark.boobooke.
[root@localhost named]# host 172.16.143.100
Host 100.143.16.172.in-addr.arpa. not found: 3(NXDOMAIN)
[root@localhost named]# host 172.16.143.50
50.143.16.172.in-addr.arpa domain name pointer client50.freedom.boobooke.
[root@localhost named]#

【实例3】安装基于chroot的DNS服务器，并将其配置成缓存Cache-only服务器，然后将客户机的查询转发到202.100.138.68和202.100.128.68的DNS服务器上。
配置named.conf文件
删除所有文件的内容，建立缓存服务器
options{
    directory "/var/named";
    forwarders {
        202.100.138.68;
        202.100.128.68;};
    forward only;
};

重启服务

[root@localhost etc]# host www.baidu.com
www.baidu.com is an alias for www.a.shifen.com.
www.a.shifen.com has address 220.181.111.148
www.a.shifen.com has address 220.181.112.143


【实例4】安装基于chroot的DNS服务器，并根据以下要求配置主要名称服务器。
（1）定义服务器的版本信息为“9.3.4”。
（2）设置根区域，以便DNS服务器在本地区域文件不能进行查询的解析时，能转到根DNS服务器查询。
（3）建立xyz.org主区域，设置允许区域复制的辅域名服务器的地址为192.168.31.134。
（4）建立以下A资源记录。
dns.xyz.org. IN A 192.168.31.1
www.xyz.org. IN A 192.168.31.2
mail.xyz.org. IN A 192.168.31.3
（5）建立以下别名CNAME资源记录。
bbs IN CNAME www
（6）建立以下邮件交换器MX资源记录
Xyz.org. IN MX 10 mail.xyz.org.
（7）建立反向解析区域31.168.192.in-addr.arpa，并为以上A资源记录建立对应的指针PTR资源记录。
[root@localhost etc]# vim named.conf

options{
        directory "/var/named";
        version "9.3.4";
        allow-transfer {172.16.141.139;};
};
zone "." {
        type hint;
        file "named.ca";

};

zone "xyz.org" {
        type master;
        file "xyz.org.zone";
};

zone "141.16.172.in-addr.arpa" {
        type master;
        file "172.16.141.zone";
       

};

[root@localhost named]# vim xyz.org.zone

$TTL 86400
@               IN      SOA     dns.xyz.org.    root (
                2011071400;
                3H;
                1H;
                1W
                1D)
@               IN      NS      dns
dns             IN      A       172.16.141.1
www             IN      A       172.16.141.2
mail            IN      A       172.16.141.3

bbs             IN      CNAME   www
xyz.org.        IN      MX      10      mail.xyz.org.

[root@localhost named]# vim 172.16.141.zone

$TTL 86400
@               IN              SOA             dns.xyz.org.    root (
                                                2011071400
                                                3H
                                                1H
                                                1W
                                                1D)
@               IN              NS              dns.xyz.org.
1               IN              PTR             dns.xyz.org.   
2               IN              PTR             www.xyz.org.   
3               IN              PTR             mail.xyz.org.  

配置好之后，一定要留意/etc/resolve.conf中，
; generated by /sbin/dhclient-script
search localdomain
nameserver 127.0.0.1
nameserver一定要是本地的回环地址，不然会错误


实例5】安装基于chroot的DNS服务器，并根据以下要求配置辅助名称服务器。
（1）建立xyz.org从区域，设置主要名称服务器的地址为192.168.31.132。
（2）建立反向解析从区域31.168.192.in-addr.arpa，设置主要名称服务器的地址为192.168.31.132。

辅助域名服务器的配置
[root@localhost yum.repos.d]# yum -y install bind-*
[root@localhost yum.repos.d]# yum -y install caching-nameserver-*
设置主配置文件

options {
        directory "/var/named";

};
zone "xyz.org" {
        type slave;
        masters { 172.16.141.132; };
        file "slaves/xyz.org.zone";

};
zone "141.16.172.in-addr.arpa" {
        type slave;
        masters { 172.16.141.132; };
        file "slaves/172.16.141.zone";
};
去到/var/named/slaves 中，此时
[root@localhost slaves]# ls
没有文件
[root@localhost slaves]# service named start
Starting named:                                            [  OK  ]
[root@localhost slaves]# ls
172.16.141.zone  xyz.org.zone
[root@localhost slaves]#
重启服务即可看到
[root@localhost slaves]# host dns.xyz.org
;; connection timed out; no servers could be reached

发现，解析不了，因为我们需要修改DNS
[root@localhost slaves]# vim /etc/resolv.conf

nameserver 127.0.0.1

[root@localhost slaves]# host dns.xyz.org
dns.xyz.org has address 172.16.141.1
即可实现