网站和网址有什么不同,佛山狮山网站建设,栖霞网站定制,国内新闻最新消息10条2021DNS介绍
DNS是一个域名系统#xff0c;在互联网环境中为域名和IP地址相互映射的一个分布式数据库 #xff0c; 能够使用户更方便的访问互联网#xff0c;而不用去记住能够被机器直接读取的IP数串。类似于生活中的114服务#xff0c;可以通过人名找到电话号码#xff0c;也…
DNS介绍
DNS是一个域名系统在互联网环境中为域名和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。类似于生活中的114服务可以通过人名找到电话号码也可以通过电话号码找到人名生活中没有那么准确的原因是人名有重名而域名是全世界唯一的。ONS协议运行在UDP协议之上使用端口号53应用场景需要域名解析的地方
DNS查询 DNS服务器部署
DNS安装
yum -y install bind bind-chroot
bind DNS主程序包bind-chroot DNS安全包改变默认DNS根目录将DNS运行在监牢模式
DNS启动
方法一不使用chroot模式启动DNS
开启开机启动
systemctl enable named
# Created symlink from /etc/systemd/system/multi-user.target.wants/named.service to /usr/lib/systemd/system/named.service.启动DNS服务
systemctl start named
方法二使用chroot模式DNS
将对应的文件移动到chroot根目录
主配文件
cp -p /etc/named.conf /var/named/chroot/etc/
chgrp named /var/named/chroot/etc/named.conf
named-checkconf /var/named/chroot/etc/named.conf区域数据库文件
cp /var/named/named.localhost /var/named/chroot/var/named/ayitula.com.zone
chgrp named /var/named/chroot/var/named/ayitula.com.zone
cp -p /var/named/named.*/var/named/chroot/var/named/启动DNS服务
开机启动
systemctl enable named-chroot.service
# Created symlink from /etc/systemd/system/multi-user.target.wants/named-chroot.service to /usr/lib/systemd/system/named-chroot.service.启动服务
systemctl start named-chroot DNS配置文件详解
默认情况下如果不安装named-chroot这个包配置文件的路径如下配置文件/etc/named.conf区域数据库文件/var/named/ 由于我们安装了named-chroot这个用于改变默认DNS配置文件的路径的包所以相对应的配置文件的路径也发生了变化。变化如下 配置文件/var/named/chroot/etc/named.conf区域数据库文件/var/named/chroot/var/named/
域名解析
正向解析
案例对yudan.com域名做解析解析要求如下www解析为A记录IP地址为192.168.10.88news做别名解析CNAME解析为www
修改主配文件 /var/named/chroot/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.
//
// See the BIND Administrators Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.htmloptions {listen-on port 53 { 192.168.10.110; };//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;//recursing-file /var/named/data/named.recursing;//secroots-file /var/named/data/named.secroots;allow-query { any; };recursion yes;//dnssec-enable yes;//dnssec-validation yes;/* Path to ISC DLV key *///bindkeys-file /etc/named.root.key;//managed-keys-directory /var/named/dynamic;pid-file /run/named/named.pid;session-keyfile /run/named/session.key;
};//logging {
// channel default_debug {
// file data/named.run;
// severity dynamic;
// };
//};zone . IN {type hint;file named.ca;
};zone yudan.com IN {// hint master slave forwardtype master;file yudan.com.zone;
}切换到/var/named/chroot/var/named/目录下
// 自己复制一个区域数据文件
cp named.localhost yudan.com.zone 修改yudan.com.zone配置文件
$TTL 1D
yudan.com. IN SOA ns1.yudan.com. rname.invalid. (0 ; serial1D ; refresh1H ; retry1W ; expire3H ) ; minimumNS ns1.yudan.com.
;A
;PTR
;Mx
;CNAME
ns1 A 192.168.10.110
www A 192.168.10.88
news CNAME www
// 检查主配文件
named-checkconf /var/named/chroot/etc/named.conf
// 检查区域数据文件
named-checkzone yudan.com /var/named/chroot/var/named/yudan.com.zone
域名解析命令
hosthost采用非交互式解析nslookupnslookup可以采用交互或非交互式解析digdig显示详细的解析流程
// host命令
[rootServer named]# host www.yudan.com
www.yudan.com has address 192.168.10.88
[rootServer named]# host news.yudan.com
news.yudan.com is an alias for www.yudan.com.
www.yudan.com has address 192.168.10.88// nslookup命令
[rootServer named]# nslookup www.yudan.com
Server: 192.168.10.110
Address: 192.168.10.110#53Name: www.yudan.com
Address: 192.168.10.88// dig命令
[rootServer named]# dig www.yudan.com; DiG 9.11.4-P2-RedHat-9.11.4-26.P2.el7_9.16 www.yudan.com
;; global options: cmd
;; Got answer:
;; -HEADER- opcode: QUERY, status: NOERROR, id: 23645
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 2;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;www.yudan.com. IN A;; ANSWER SECTION:
www.yudan.com. 86400 IN A 192.168.10.88;; AUTHORITY SECTION:
yudan.com. 86400 IN NS ns1.yudan.com.;; ADDITIONAL SECTION:
ns1.yudan.com. 86400 IN A 192.168.10.110;; Query time: 0 msec
;; SERVER: 192.168.10.110#53(192.168.10.110)
;; WHEN: 日 4月 27 11:44:00 CST 2025
;; MSG SIZE rcvd: 92
反向解析
案例对www.yudan.com做反向解析其对应的lP地址为192.168.10.88
配置主配文件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.
//
// See the BIND Administrators Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.htmloptions {listen-on port 53 { 192.168.10.110; };//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;//recursing-file /var/named/data/named.recursing;//secroots-file /var/named/data/named.secroots;allow-query { any; };recursion yes;//dnssec-enable yes;//dnssec-validation yes;/* Path to ISC DLV key *///bindkeys-file /etc/named.root.key;//managed-keys-directory /var/named/dynamic;pid-file /run/named/named.pid;session-keyfile /run/named/session.key;
};//logging {
// channel default_debug {
// file data/named.run;
// severity dynamic;
// };
//};zone . IN {type hint;file named.ca;
};zone yudan.com IN {// hint master slave forwardtype master;file yudan.com.zone;
};// 反向解析IP地址
zone 10.168.192.in-addr.arpa IN {type master;file 192.168.10.arpa;
};配置区域数据库文件192.168.10.arpa
$TTL 1D
10.168.192.in-addr.arpa. IN SOA ns1.yudan.com. rname.invalid. (0 ; serial1D ; refresh1H ; retry1W ; expire3H ) ; minimumNS ns1.yudan.com.
88 PTR www.yudan.com.
主从同步
DNS主从
主配置文件不会同步同步的是区域数据库文件
更改slave节点的主配文件
//
// 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.
//
// See the BIND Administrators Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.htmloptions {listen-on port 53 { 192.168.10.120; };//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;//recursing-file /var/named/data/named.recursing;//secroots-file /var/named/data/named.secroots;allow-query { any; };recursion yes;//dnssec-enable yes;//dnssec-validation yes;/* Path to ISC DLV key *///bindkeys-file /etc/named.root.key;//managed-keys-directory /var/named/dynamic;pid-file /run/named/named.pid;session-keyfile /run/named/session.key;
};//logging {
// channel default_debug {
// file data/named.run;
// severity dynamic;
// };
//};zone . IN {type hint;file named.ca;
};zone yudan.com IN {// hint master slave forwardtype slave;file yudan.com.zone;masters { 192.168.10.110; };
};zone 10.168.192.in-addr.arpa IN {type slave;file 192.168.10.arpa;masters { 192.168.10.110; };
};智能解析
在我们访问WEB的时候发现有的网站打开的速度非常快有的网站打开的非常慢这是为什么呢原因就是很多公司为了提升用户的体验自己的网站使用了CDN内容加速服务让你直接在你本地城市的服务器上拿数据并展示给你看。什么是CDN我们暂且理解为本地缓存服务器就好那么你是怎么准确知道你本地的缓存服务器的呢因为很多CDN公司的DNS使用了智能解析服务根据你的源IP判断你属于哪个城市让后再把本地的缓存服务器解析给你你就会直接去找该服务器拿数据了。
在DNS中植入全世界的IP库以及IP对应的地域当用户来请求解析时DNS会根据其源IP来定位他属于哪个区域然后去找这个区域的view视图查询对应的域名的区域数据库文件做解析。从而使得不同地域的用户解析不同。
//
// 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.
//
// See the BIND Administrators Reference Manual (ARM) for details about the
// configuration located in /usr/share/doc/bind-{version}/Bv9ARM.htmloptions {listen-on port 53 { 192.168.10.110; };//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;//recursing-file /var/named/data/named.recursing;//secroots-file /var/named/data/named.secroots;allow-query { any; };recursion yes;//dnssec-enable yes;//dnssec-validation yes;/* Path to ISC DLV key *///bindkeys-file /etc/named.root.key;//managed-keys-directory /var/named/dynamic;pid-file /run/named/named.pid;session-keyfile /run/named/session.key;masterfile-format text;
};//logging {
// channel default_debug {
// file data/named.run;
// severity dynamic;
// };
//};acl bj {192.168.10.110;
};acl sh {1.2.2.2;
};view beijing {match-clients { bj; };zone . IN {type hint;file named.ca;};zone yudan.com IN {// hint master slave forwardtype master;file yudan.com.zone.bj;};
}; // 闭合 beijing viewview shanghai {match-clients { sh; };zone . IN {type hint;file named.ca;};zone yudan.com IN {// hint master slave forwardtype master;file yudan.com.zone.sh;};
}; // 闭合 shanghai viewview other {match-clients { bj; };zone . IN {type hint;file named.ca;};zone yudan.com IN {// hint master slave forwardtype master;file yudan.com.zone.ot;};
}; // 闭合 other view
