标签：dns
我们知道相同网段内各网络设备之间是基于mac通信，而跨网络的不同主机之间是基于IP地址通信。随着世界主机数量爆炸式的增长，对于记住数目众多IP和想访问未知对方IP的主机成为一个痛点。通过基于人们熟知的文字访问主机应运而生。
DNS（Domain Name System，域名系统），因特网上作为域名和IP地址相互映射的一个分布式数据库，能够使用户更方便的访问互联网，而不用去记住能够被机器直接读取的IP数串。通过主机名，最终得到该主机名对应的IP地址的过程叫做域名解析（或主机名解析）。
DNS是一项十分基础服务，今天我们实现在linux下安装bind，DNS主从复制，view视图，转发，子域授权等功能。
安装包
bind-9.8.2-0.37.rc1.el6.x86_64.rpm
bind-libs-9.8.2-0.37.rc1.el6.x86_64.rpm
bind-utils-9.8.2-0.37.rc1.el6.x86_64.rpm
可直接使用 yum install -y bind安装自动解决依赖关系或者使用rpm分别安装各个包。
编辑/etc/named.conf配置文件
[root@test-2 ~]# cp /etc/named.conf /etc/named.conf_bak #先备份
[root@test-2 ~]# vi /etc/named.conf #先简单配置下
options {
listen-on port 53 { 10.0.0.7; }; #监听IP及端口
directory "/var/named";
allow-query { any; }; #允许所有IP查询
recursion yes; #允许递归
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
zone "." IN {
type hint;
file "named.ca";
};
zone "magedu.com" IN { #配置正向解析domain为magedu
type master; #模式为master
file "magedu/magedu.zone"; #区域文件存放地点
};
zone "0.0.10.a.in-addr.arpa" IN { #配置反像解析
type master; #模式为master
file "magedu/10.0.0.zone";
};
#include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";
[root@test-2 magedu]# named-checkconf #检查配置文件创建目录magedu，用于存放magedu域正向，反向解析文件
[root@test-2 ~]# cd /var/named/ [root@test-2 named]# mkdir magedu [root@test-2 named]# chown -R root:named magedu #设置属主和数组 [root@test-2 named]# chmod -R 750 magedu #设置权限为750，否则会提示权限问题 [root@test-2 named]# ls data dynamic magedu named.ca named.empty named.localhost named.loopback slaves
创建正向解析和反向解析文件
[root@test-2 named]# cd magedu/ [root@test-2 magedu]# vi magedu.zone #创建正向解析文件 $TTL 600 @ IN SOA magedu.com. dnsadmin.magedu.com. ( 20150915001 3m 3m 3d 1d) IN NS ns1.magedu.com. ns1 IN A 10.0.0.7 www IN A 10.0.0.11 bao IN A 10.0.0.12 [root@test-2 magedu]# vi 10.0.0.zone #创建反向解析文件 $TTL 600 @ IN SOA magedu.com. dnsadmin.magedu.com. ( 20150915001 3m 3m 3d 1d) IN NS ns1.magedu.com. 7 IN PTR ns1.magedu.com. 11 IN PTR www.magedu.com. 12 IN PTR bao.magedu.com. ~ [root@test-2 magedu]# chmod 640 10.0.0.zone magedu.zone #设置权限 [root@test-2 magedu]# named-checkzone magedu.com magedu.zone #检查配置文件是否正确 zone magedu.com/IN: loaded serial 2971045817 OK [root@test-2 magedu]# named-checkzone 0.0.10.a.in-addr.arpa 10.0.0.zone zone 0.0.10.a.in-addr.arpa/IN: loaded serial 2971045817 OK
启动named，验证DNS是否能够正解，反解
[root@test-2 magedu]# /etc/init.d/named start #启动配置named Starting named: [ OK ] [root@test-2 magedu]# dig -t A www.magedu.com @10.0.0.7 #正解www.magedu.com ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.37.rc1.el6 <<>> -t A www.magedu.com @10.0.0.7 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19681 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; QUESTION SECTION: ;www.magedu.com. IN A ;; ANSWER SECTION: www.magedu.com. 600 IN A 10.0.0.11 ;; AUTHORITY SECTION: magedu.com. 600 IN NS ns1.magedu.com. ;; ADDITIONAL SECTION: ns1.magedu.com. 600 IN A 10.0.0.7 ;; Query time: 4 msec ;; SERVER: 10.0.0.7#53(10.0.0.7) ;; WHEN: Tue Sep 15 21:06:12 2015 ;; MSG SIZE rcvd: 82 [root@test-2 magedu]# dig -x 10.0.0.11 @10.0.0.7 #反解10.0.0.11 ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.37.rc1.el6 <<>> -x 10.0.0.11 @10.0.0.7 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9952 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;11.0.0.10.in-addr.arpa. IN PTR ;; ANSWER SECTION: 11.0.0.10.in-addr.arpa. 600 IN PTR www.magedu.com. ;; AUTHORITY SECTION: 0.0.10.in-addr.arpa. 600 IN NS ns1.magedu.com. ;; ADDITIONAL SECTION: ns1.magedu.com. 600 IN A 10.0.0.7 ;; Query time: 1 msec ;; SERVER: 10.0.0.7#53(10.0.0.7) ;; WHEN: Tue Sep 15 21:24:41 2015 ;; MSG SIZE rcvd: 102
经验证，DNS已OK
view视图，可以实现，不同客户端IP解析域名时得到不同解析，而相同IP每次解析IP相同，模拟智能DNS实现区域负载的目的。
下面搭建view视图
修改配置文件/etc/named.conf
options {
listen-on port 53 { 10.0.0.7; }; #由于没有加路由，只有让不同网段使用不同的DNS
listen-on port 53 { 192.168.0.106; };
directory "/var/named";
allow-query { any; };
recursion yes;
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
view "lan" { #配置一个叫lan的视图
match-clients { 192.168.0.0/24; }; #设置不同网段使用不同的解析文件
zone "." IN {
type hint;
file "named.ca";
};
zone "magedu.com" IN {
type master;
file "magedu/magedu.zone";
};
zone "0.0.10.in-addr.arpa" IN {
type master;
file "magedu/10.0.0.zone";
};
};
view "wlan" { #配置一个叫wlan的视图
match-clients { 10.0.0.0/24; };
zone "." IN {
type hint;
file "named.ca";
};
zone "magedu.com" IN {
type master;
file "magedu/magedu.zone.wlan";
};
zone "0.0.10.in-addr.arpa" IN {
type master;
file "magedu/10.0.0.zone.wlan";
};
};
#include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";根据/etc/named.conf配置，需要新加magedu.zone.wlan，10.0.0.zone.wlan配置文件
[root@test-2 magedu] cp 10.0.0.zone 10.0.0.zone.wlan #嘿嘿，偷个懒，然后再修改下里面内容 [root@test-2 magedu] cp magedu.zone magedu.zone.wlan [root@test-2 magedu] chwon :named magedu.zone.wlan 10.0.0.zone.wlan #修改属组 [root@test-2 magedu] vi 10.0.0.zone.wlan $TTL 600 @ IN SOA magedu.com. dnsadmin.magedu.com. ( 20150915003 3m 3m 3d 1d) IN NS ns1.magedu.com. 7 IN PTR ns1.magedu.com. 111 #原来的11改成了111 IN PTR www.magedu.com. 122 #原来的12改成了122 IN PTR bao.magedu.com. [root@test-2 magedu] vi magedu.zone.wlan $TTL 600 @ IN SOA magedu.com. dnsadmin.magedu.com. ( 20150915003 3m 3m 3d 1d) IN NS ns1.magedu.com. ns1 IN A 10.0.0.7 www IN A 10.0.0.111 #把原来的11改成了111 bao IN A 10.0.0.122 #把原来的12改成了122
根据lan和wlan配置文件，如果是10.0.0.0/24网段的主机去dig -t a www.magedu.com则会返回10.0.0.111。
如果是192.168.0.0/24网段的主机去dig -t a www.magedu.com则会返回10.0.0.11。
下面我们验证是否正确
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:4e:f0:1a brd ff:ff:ff:ff:ff:ff inet 192.168.0.105/24 brd 192.168.0.255 scope global eth0 #192.168.0.105 inet6 fe80::20c:29ff:fe4e:f01a/64 scope link valid_lft forever preferred_lft forever 3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:4e:f0:2e brd ff:ff:ff:ff:ff:ff inet 10.0.0.8/24 brd 10.0.0.255 scope global eth1 #10.0.0.8 inet6 fe80::20c:29ff:fe4e:f02e/64 scope link valid_lft forever preferred_lft forever [root@test-3 ~]# dig -t a www.magedu.com @10.0.0.7 ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6 <<>> -t a www.magedu.com @10.0.0.7 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 43891 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; QUESTION SECTION: ;www.magedu.com. IN A ;; ANSWER SECTION: www.magedu.com. 600 IN A 10.0.0.111 #使用10.0.0.7解析的结果 ;; AUTHORITY SECTION: magedu.com. 600 IN NS ns1.magedu.com. ;; ADDITIONAL SECTION: ns1.magedu.com. 600 IN A 10.0.0.7 ;; Query time: 8 msec ;; SERVER: 10.0.0.7#53(10.0.0.7) ;; WHEN: Tue Sep 15 22:11:09 2015 ;; MSG SIZE rcvd: 82 [root@test-3 ~]# dig -t a www.magedu.com @192.168.0.106 ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6 <<>> -t a www.magedu.com @192.168.0.106 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 51307 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1 ;; QUESTION SECTION: ;www.magedu.com. IN A ;; ANSWER SECTION: www.magedu.com. 600 IN A 10.0.0.11 #使用192.168.0.106的ip解析的结果 ;; AUTHORITY SECTION: magedu.com. 600 IN NS ns1.magedu.com. ;; ADDITIONAL SECTION: ns1.magedu.com. 600 IN A 10.0.0.7 ;; Query time: 4 msec ;; SERVER: 192.168.0.106#53(192.168.0.106) ;; WHEN: Tue Sep 15 22:16:44 2015 ;; MSG SIZE rcvd: 82
标签：dns
原文地址：http://iznowow.blog.51cto.com/6232028/1695151
