linux 高速缓存DNS

高速缓存DNS

将虚拟机desktop设置为高速缓存DNS服务器

yum install bind 

systemctl start named   ##若无法启动则按键盘 生成加密内容
systemctl stop firewalld 
systemctl disable firewalld 

设置desktop的网关为真机ip
vim /etc/sysconfig/network-scripts/ifcfg-eth0
GATEWAY=172.25.254.76
注释掉DNS

vim /etc/named.conf    
listen-on port 53 { any; }; ##使此主机上任意IP都可打开53端口提供服务
allow-query { any; };  ##使其他主机IP可以连接此DNS服务
forwarders { 114.114.114.114; };   ##设置解析域名地址为 114.114.114.114
dnsses-validation no;   ##取消dns验证
systemctl restart named  

netstat -antlupe | grep named ##查看服务named
a：所有
n:不解析
t:tcp
l:地址端口信息
u:udp
p:进程
e:扩展信息

dig www.baidu.com 

在真机中测试:

真机应开启防火墙地址伪装功能使虚拟机可以链接网络

vim /etc/resolve.conf 
nameserver 172.25.254.160      ##将DNS设置为虚拟机ip

dig www.baidu.com    

dns的正向解析

vim /etc/named.rfc1912.zone
zone "westos.com" IN {
	type master;
	file "westos.com.zone";
	allow-upadte { none; };
};

cd /var/named/
cp -p named.localhost westos.com.zone
vim westos.com.zone

$TTL 1D	
@	IN SOA dns.westos.com. root.westos.com. (   ##@表示westos.com SOA记录表明了谁是这个区域的所有者可以修改这个区域 此 DNS 名称服务器是为该 DNS 域中的数据的信息的最佳来源
					0	; serial
					1D	; refresh
					1H	; retry
					1W	; expire
					3H )	; minimum

	NS	dns.westos.com.     ##NS表明谁对某个区域有解释权 用来指定该域名由哪个DNS服务器来进行解析
dns	A	172.25.254.160
www	A	172.25.254.111
##NS记录和SOA记录是任何一个DNS区域都不可或缺的两条记录，NS记录也叫名称服务器记录，用于说明这个区域有哪些DNS服务器负责解析，SOA记录说明负责解析的DNS服务器中哪一个是主服务器。

systemctl restart named

测试：

在测试主机中
vim /etc/resolv.conf
nameserver 172.25.254.160

dig www.westos.com

		NS	dns.westos.com.
www		CNAME	bbs.a.westos.com.
bbs.a		A	172.25.254.222
bbs.a		A	172.25.254.111    ##完成轮换
westos.com.	MX 1	mail.westos.com.
mail		A	172.25.254.200	##给westos.com 发送邮件将发送给172.25.254.200

测试轮换：

测试邮件：

反向解析

vim /etc/named.rfc1912.zones
zone "254.25.172.in-addr.arpa" IN {
	type master;
	file "172.25.254.ptr";
	allow-update { none; };
};

cd /var/named
cp -p named.loopback 172.25.254.ptr

vim 172.25.254.ptr
$TTL 1D	
@	IN SOA dns.westos.com. root.westos.com. (   
					0	; serial
					1D	; refresh
					1H	; retry
					1W	; expire
					3H )	; minimum

	NS	dns.westos.com.     
dns	A	172.25.254.160
100	PTR	dns.westos.com.
111	PTR	www.westos.com.

systemctl restart named

测试：

dig -x 172.25.254.111

DNS双向解析

vim /etc/named.conf
view localnet {
	match-clients { localhost; };
	zone "." IN {
		type hint;
		file "named.ca";
};
include "/etc/named.rfc1912.zones";
};
view internet {
	match-clients { any; };
	zone "." IN {
		type hint;
		file "named.ca";
 };
include "/etc/named.rfc1912.inters";
};

cp -p /etc/named.rfc1912.zones /etc/named.rfc1912.zones.initers

vim /etc/named.rfc1912.zones.inters
zone "westos.com" IN {
	type master;
	file "westos.com.inter";
	allow-update { none; };
};

cp -p westos.com.zone westos.com.inter
vim westos.com.inter
:%s/172.25.254/192.168.0/g

systemctl restart named

其他主机IP登陆时：

本机IP登陆时：

辅助DNS

主DNS的设定

vim /etc/named.rfc1912.zones
zone "westos.com" IN {
	type master;
	file "westos.com.zone";
	allow-update { none; };
	also-notify { 172.25.254.80; };     ##告诉 172.25.254.80 修改
};

systemctl restart named

注意：每次更改A记录文件后必须更改serial的数值，这个数值最大10位

辅助DNS上

yum install bind -y
systemctl restart named 
systemctl stop firewalld

vim /etc/named.conf

vim /etc/named.rfc1912.zones
zone "westos.com" IN {
	type slave;
	masters { 172.25.254.160; };
	file "slaves/westos.com.zone";  ##同步172.25.254.160中的westos.com.zone文件
	allow-update { none; };
};

systemctl restart named

测试

vim /etc/resolv.conf
nameserver 172.25.254.80

dig www.westos.com

7.DNS的远程更新

基于IP的

vim /etc/named.rfc1912.zones
zone "westos.com" IN {
	type master;
	file "westos.com.zone";
	allow-update { 172.25.254.80; };
	also-notify { 172.25.254.80; }; 
};

chmod 770 /var/named/

systemctl restart named

测试：
在80这台主机上

nsupdate
> server 172.25.254.160		##添加
> update add hello.westo.com 86400 A 172.25.254.111
> send
> server 172.25.254.160		##删除
> update delete hello.westos.com
> send

基于key:

dnssec-keygen -a HMAC-MD5 -b 128 -n HOST westos

cp /etc/rndc.key /etc/westos.key -p

vim /etc/westos.key
key "westos" {
	algorithm hmac-md5;
	secret "ndsadasdadsa==";
};

vim /etc/named.conf
include "/etc/westos.key";

vim /etc/named.rfc1912.zones
zone "westos.com" IN {
	type master;
	file "westos.com.zone";
	allow-update { key westos; };
	also-notify { 172.25.254.80; };
};

systemctl restart named

测试：

scp Kwestos.+157+59719.* [email protected]:/mnt/

在172.25.254.80

nsupdate -k Kwestos.+157+59719.key
>server 172.25.254.160
>update add hello.westos.com 86400 A 172.25.254.222
>send
>quit