Internet域名空间
Internet域名空间结构为一棵倒置的树,并进行层次划分。
由树根到树枝,也就是从DNS根到下面的节点,按照不同的层次,进行了统一的命名。
域名空间最顶层,DNS根称为根域(root)。
根域的下一层为顶级域,又称为一级域。
其下层为二级域,再下层为二级域的子域,按照需要进行规划,可以为多级。
所以对域名空间整体进行划分,由最顶层到下层,可以分成:根域、顶级域(一级域)
二级域、子域,其中域中能包含主机和子域。
区(Zone) 域:Domain,逻辑概念
区域:zone,物理概念
区是DNS名称空间的一个连续部分,其包含了一组存储在DNS
服务器上的资源记录。每个区都位于一个特殊的域节点,但区并不是域。
DNS域是名称空间的一个分支,而区一般是存储在文
件中的DNS名称空间的某一部分,可以包括多个域。一个域可
以再分成几部分,每个部分或区可以由一台DNS服务器控制。
使用区的概念,DNS服务器回答关于自己区中主机的查询,它是哪个区的授权服务器。
正向解析和反向解析
正反向解析技术不同,因此不应该存放于同一个数据库文件中进
1)正向解析
正向解析是指域名到IP地址的解析过程。
2)反向解析
反向解析是从IP地址到域名的解析过程。反向解析的作用为服务器的身份验证。
BInd的基本概况:
主配置文件:定义区域/etc/named.conf
1 options { listen-on port 53 { 172.16.249.24; }; listen-on-v6 port 53 { ::1; }; directory "/var/named"; 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 { localhost; }; 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"; }; 2 logging { channel default_debug { file "data/named.run"; severity dynamic; }; 3 zone "." IN { type hint; file "named.ca"; };
正向解析
定义配置文件域为"wowowo.com"
options { directory"/var/named"; }; zone "." IN { type hint; file "named.ca"; }; zone "localhost." IN { type master; file "named.localhost"; }; zone "1.0.0.127.in-addr.arpa" IN { type master; file "named.loopback"; }; zone "wowowo.com." IN { type master; file "wowowo.com.zone"; };
资源记录中的文件名一定与配置文件中的定义的名称一致
配置资源记录
$TTL 600 @ IN SOA dns.wowowo.com. admin.wowowo.com. ( 2015020001 2H 10M 7D 1D ) IN NS dns.wowowo.com. IN MX 10 mail dns IN A 192.168.1.110 mail IN A 192.168.1.111 www IN A 192.168.1.110 ftp IN CNAME www
方向解析
zone "1.168.192.in-addr.arpa." IN { type master; file "192.168.1.zone"; }; 语法格式
资源记录的格式
$TTL 600 @ IN SOA dns.wowowo.com. admin.wowowo.com. ( 2015020002 2H 10M 7D 1D ) IN NS dns.wowowo.com. 110 IN PTR dns.wowowo.com. 110 IN PTR www.wowowo.com. 111 IN PTR mail.wowowo.com.
主从:(bind的版本主的可以低于从)
向区域中添加从服务器的关键两步
在上级获得授权
在区域数据文件中为从服务器添加一条NS记录和对应的A或PTR记录
格式为正向 (反向)同步 42 zone "wowowo.com" IN { 43 type slave; 44 masters { 192.168.1.110; }; 45 file "slaves/wowowo.com.zone"; 46 }; 47 48 zone "1.168.192.in-addr.arpa" IN { 49 type slave; 50 masters { 192.168.1.110; }; 51 file "slaves/192.168.1.zone"; 52 };
资源记录配置(主服务器上要添加一条对应从服务器的NS记录,否则不会通知从服务器更新)
主服务器/var/named/正向配置格式 $TTL 600 @ IN SOA dns.wowowo.com. admin.wowowo.com. ( 2015020005 3M 6M 9M 1D ) IN NS dns.wowowo.com. IN NS dns1.wowowo.com. IN MX 10 mail dns IN A 192.168.1.110 mail IN A 192.168.1.111 dns1 IN A 192.168.1.108 www IN A 192.168.1.110 ftp IN CNAME www img IN A 192.168.1.112
反向配置格式 $TTL 600 @ IN SOA dns.wowowo.com. admin.wowowo.com. ( 2015020004 2H 10M 7D 1D ) IN NS dns.wowowo.com. IN NS dns1.wowowo.com. 110 IN PTR dns.wowowo.com. 110 IN PTR www.wowowo.com. 111 IN PTR mail.wowowo.com. 108 IN PTR dns1.wowowo.com. 112 IN PTR img.wowowo.com.
BIND子域授权的实现:
在父域的配置文件中添加如下项:
授权的子区域名称
子区域的名称服务器
子区域的名称服务器的IP地址
[root@localhost named]# vim /var/named/wowowo.com.zone $TTL 600 @ IN SOA dns.wowowo.com. admin.wowowo.com. ( 2015020008 3M 6M 9M 1D ) IN NS dns.wowowo.com. IN NS dns1.wowowo.com. IN MX 10 mail dns IN A 192.168.1.103 mail IN A 192.168.1.111 dns1 IN A 192.168.1.108 www IN A 192.168.1.103 ftp IN CNAME www img IN A 192.168.1.112 hehe IN NS dns.hehe.wowowo.com. dns.hehe.wowowo.com. IN A 192.168.1.106 ~
添加一条NS记录和A记录(记得别忘记载入)
这条记录就是授权子域的链接简称(glue record:胶水效果)
子域区空间增加
[root@localhost named]# vim /etc/named.rfc1912.zones zone "hehe.wowowo.com" IN { type master; file "hehe.wowowo.com.zone"; };
对应文件名
[root@localhost named]# vim /var/named/hehe.wowowo.com.zone $TTl 600 @ IN SOA dns.hehe.wowowo.com. dnsadmin.hehe.wowowo.com. ( 2015092101 1H 5M 3D 1D ) IN NS dns IN MX 10 mail dns IN A 192.168.1.106 www IN A 192.168.1.116 mail IN A 192.168.1.119 ~
子域解析父域
子域配置文件中需添加的选项
}; zone "wowowo.com" IN { type forward; forwarders { 192.168.1.108; }; };
[root@localhost named]# dig -t A www.wowowo.com @192.168.1.106 ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6 <<>> -t A www.wowowo.com @192.168.1.106 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28463 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;www.wowowo.com. IN A ;; ANSWER SECTION: www.wowowo.com. 600 IN A 192.168.1.103 ;; AUTHORITY SECTION: wowowo.com. 600 IN NS dns.wowowo.com. wowowo.com. 600 IN NS dns1.wowowo.com. ;; ADDITIONAL SECTION: dns1.wowowo.com. 600 IN A 192.168.1.108 dns.wowowo.com. 600 IN A 192.168.1.103 ;; Query time: 3 msec ;; SERVER: 192.168.1.106#53(192.168.1.106) ;; WHEN: Wed Sep 23 18:22:17 2015 ;; MSG SIZE rcvd: 117
假设一种情况:子域连客户端 解析子域的直接转向自己负责的 否则就直接转入能解析互联网的域名
需要在子域主配置文件中写入forward first;forwarders { ip };
options { # listen-on port 53 { 127.0.0.1; }; # listen-on-v6 port 53 { ::1; }; directory "/var/named"; # 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 { localhost; }; 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"; forward first; forwarders { 192.168.1.0 }; };