DNS是域名系統(Domain Name System)的縮寫,是因特網的一項核心服務,它能提供域名與IP地址之間對應關係的轉換服務。
這樣我們就可以更方便地去訪問互聯網了,不用去記住那一串IP數字。本文檔主要是說明如何把一臺CentOS主機配置成一個DNS
服務器,以便能提供域名解析服務。
(1) DNS服務器端配置
操作系統:CentOS 6.4
IP地址:172.16.1.4
DNS軟件:Bind 9.8
測試域名:realhostip.com
作用:主要提供解析realhostip.com域名的服務
1. 安裝bind
# yum install bind
2. 修改/etc/named.conf配置文件
# vi /etc/named.conf
//
// named.conf
//
// Provided by Red Hat bind package to configure the ISC BIND named(8) DNS
// server as a caching only nameserver (as a localhost DNS resolver only).
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
options {
listen-on port 53 { any; }; //開啓監聽端口53,接受任意IP連接
listen-on-v6 port 53 { ::1; }; //支持IP V6
directory "/var/named"; //所有的正向反向區域文件都在這個目錄下創建
dump-file "/var/named/data/cache_dump.db";
statistics-file "/var/named/data/named_stats.txt";
memstatistics-file "/var/named/data/named_mem_stats.txt";
allow-query { 0.0.0.0/0; }; //允許任意IP查詢
recursion yes;
dnssec-enable yes;
dnssec-validation yes;
dnssec-lookaside auto;
/* Path to ISC DLV key */
bindkeys-file "/etc/named.iscdlv.key";
managed-keys-directory "/var/named/dynamic";
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
zone "." IN {
type hint;
file "named.ca";
};
include "/etc/named.rfc1912.zones"; //主要配置文件
include "/etc/named.root.key";
3. 修改/etc/named.rfc1912.zones文件,添加realhostip.com的正向和反向區域
# vi /etc/ named.rfc1912.zones
// named.rfc1912.zones:
//
// Provided by Red Hat caching-nameserver package
//
// ISC BIND named zone configuration for zones recommended by
// RFC 1912 section 4.1 : localhost TLDs and address zones
// and http://www.ietf.org/internet-drafts/draft-ietf-dnsop-default-local-zones-02.txt
// (c)2007 R W Franks
//
// See /usr/share/doc/bind*/sample/ for example named configuration files.
//
zone "localhost.localdomain" IN {
type master;
file "named.localhost";
allow-update { none; };
};
zone "localhost" IN {
type master;
file "named.localhost";
allow-update { none; };
};
zone "1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {
type master;
file "named.loopback";
allow-update { none; };
};
zone "1.0.0.127.in-addr.arpa" IN {
type master;
file "named.loopback";
allow-update { none; };
};
zone "0.in-addr.arpa" IN {
type master;
file "named.empty";
allow-update { none; };
};
//realhostip.com的正向區域
zone "realhostip.com" IN {
type master;
file "named.realhostip.com";
allow-update { none; };
};
//realhostip.com的反向區域
zone "1.16.172.in-addr.arpa" IN {
type master;
file "172.16.1.arpa";
allow-update { none; };
};
這裏需要注意的是,添加反向區域時,網絡號要反過來寫(網絡號是IP地址與子網掩碼進行與操作後的結果)。
例如,我現在配置的網絡號172.16.1這個網段,那麼它的反向區域是1.16.172.in-addr.arpa。區域裏面的file
字段表明解析時的數據來源文件,接下來我們去創建named.realhostip.com和172.16.1.arpa文件。
4. 創建正向和反向區域資源文件
在配置named.conf時,指明的資源文件目錄是/var/named,故先進入該目錄。
# cd /var/named
# vi named.realhostip.com
$TTL 1D
@ IN SOA realhostip.com. rname.invalid. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS @
A 127.0.0.1
AAAA ::1
172-16-1-50 IN A 172.16.1.50
172-16-1-51 IN A 172.16.1.51
以上我添加了兩條記錄,其中172-16-1-50 IN A 172.16.1.50表明域名172-16-1-50.realhostip.com對應的IP地址爲172.16.1.50。
如果需要添加多條,按此類似添加,留意realhostip.com後面的那個不起眼的點(.)。
# vi 172.16.1.arpa
$TTL 1D
@ IN SOA realhostip.com. rname.invalid. (
0 ; serial
1D ; refresh
1H ; retry
1W ; expire
3H ) ; minimum
NS @
AAAA ::1
50 PTR 172-16-1-50.realhostip.com.
51 PTR 172-16-1-51.realhostip.com.
以上我也添加了兩條記錄,其中50 PTR 172-16-1-50.realhostip.com表明IP地址172.16.1.50對應的
域名爲172-16-1-50.realhostip.com。如果要添加多條,按此類似添加,留意realhostip.com後面的那個不起眼的點(.)。
5. 啓動named服務
#service named start
至此,DNS服務器端的配置已完成,下面我們稍微配置一下客戶端來測試我們的DNS服務器是否正常工作。
(2) 客戶端配置
操作系統:windows和Linux都可以,我這裏是CentOS 6.4
IP地址:能夠ping通DNS服務器的IP(172.16.1.4)都可以,我這裏是172.16.1.104
作用:測試DNS服務器是否正常工作。
1. 安裝bind-utils包,以便能使用nslookup、dig和host工具
yum install bind-utils
2. 修改DNS配置使用我們的DNS服務器
vi /etc/resolv.conf
nameserver 172.16.1.4
nameserver 192.168.13.31
nameserver 172.16.1.1
如果是windows客戶端,需要在本地連接屬性裏面修改,如下圖:
resolv.conf文件中可能會有多個nameserver,必須把我們的DNS服務器放在所有nameserver的最前面,
這樣當需要解析域名時,第一個使用的就是我們配置的DNS服務器,其它的都是候選項。
3. 正向解析測試,使用nslookup命令
#nslookup
> 172-16-1-50.realhostip.com
Server: 172.16.1.4
Address: 172.16.1.4#53
Name: 172-16-1-50.realhostip.com
Address: 172.16.1.50
>
> 172-16-1-51.realhostip.com
Server: 172.16.1.4
Address: 172.16.1.4#53
Name: 172-16-1-51.realhostip.com
Address: 172.16.1.51
>
從結果可以看到,我們配置的兩個域名都能成功解析,並且DNS服務器就是我們配置的那個服務器。
4. 反向解析,使用nslookup命令
#nslookup
>
> 172.16.1.51
Server: 172.16.1.4
Address: 172.16.1.4#53
51.1.16.172.in-addr.arpa name = 172-16-1-51.realhostip.com.
>
>
> 172.16.1.50
Server: 172.16.1.4
Address: 172.16.1.4#53
50.1.16.172.in-addr.arpa name = 172-16-1-50.realhostip.com.
>
>
從結果來看,可以正確解析我們的IP地址,並且DNS服務器就是我們配置的那個服務器。
5. 查看realhostip.com這個域名是哪個DNS服務器管理的,使用dig命令
# dig -t ns realhostip.com
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> -t ns realhostip.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37964
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 2
;; QUESTION SECTION:
;realhostip.com. IN NS
;; ANSWER SECTION:
realhostip.com. 86400 IN NS realhostip.com.
;; ADDITIONAL SECTION:
realhostip.com. 86400 IN A 172.16.1.4
realhostip.com. 86400 IN AAAA ::1
;; Query time: 1 msec
;; SERVER: 172.16.1.4#53(172.16.1.4)
;; WHEN: Wed Oct 23 14:15:22 2013
;; MSG SIZE rcvd: 90
6. 使用dig命令進行正向解析
# dig 172-16-1-50.realhostip.com
; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> 172-16-1-50.realhostip.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21109
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2
;; QUESTION SECTION:
;172-16-1-50.realhostip.com. IN A
;; ANSWER SECTION:
172-16-1-50.realhostip.com. 86400 IN A 172.16.1.50
;; AUTHORITY SECTION:
realhostip.com. 86400 IN NS realhostip.com.
;; ADDITIONAL SECTION:
realhostip.com. 86400 IN A 172.16.1.4
realhostip.com. 86400 IN AAAA ::1
;; Query time: 1 msec
;; SERVER: 172.16.1.4#53(172.16.1.4)
;; WHEN: Wed Oct 23 14:17:57 2013
;; MSG SIZE rcvd: 118
注意:
windows客戶端上只有nslookup工具。
(3) 相關資料
[1] http://www.linuxidc.com/Linux/2012-03/56086.htm
[2] http://www.linuxidc.com/Linux/2013-07/87440.htm
[3] http://wenku.baidu.com/view/e7095ad7b14e852458fb57db.html
[4] http://blog.csdn.net/flyoxs/article/details/5940415
[5] http://yuelei.blog.51cto.com/202879/106228
[6] http://yuelei.blog.51cto.com/202879/109657
[7] http://future.blog.51cto.com/26959/90603
[8] http://www.linuxdiyf.com/viewarticle.php?id=16156
[9] http://linux.chinaunix.net/techdoc/install/2007/10/25/970650.shtml