dns 主備搭建
環境說明
系統:CentOS 7.6 x86_64
主master:10.0.0.182
備slave:10.0.0.115
1、安裝主要包,在主備機器都執行如下命令
yum install bind bind-utils bind-chroot -y
2、進行配置配置
主master上配置
/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 Administrator's Reference Manual (ARM) for details about the // configuration located in /usr/share/doc/bind-{version}/Bv9ARM.html options { listen-on port 53 { any; }; 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; }; notify yes; recursion yes; dnssec-enable yes; dnssec-validation yes; bindkeys-file "/etc/named/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; }; }; zone "." IN { type hint; file "named.ca"; }; #include "/etc/named/named.rfc1912.zones"; include "/etc/named/named.sx.zones"; include "/etc/named/named.root.key";
/etc/named/named.sx.zones,由於該文件是自定義的文件,需要手動更改下文件權限,
chown root.named /etc/named/named.sx.zones
zone "sx" IN { type master; file "zones/sx.zone"; allow-update { 10.0.0.115; }; also-notify { 10.0.0.115; }; allow-transfer { 10.0.0.115; }; }; zone "sx.com" IN { type master; file "zones/sx.com.zone"; allow-update { 10.0.0.115; }; also-notify { 10.0.0.115; }; allow-transfer { 10.0.0.115; }; };
在/var/named/ 下創建zones目錄,並更改用戶屬主和屬組
mkdir /var/named/zones
chown named.named /var/named/zones
cat /var/named/zones/sx.zone
$TTL 600 @ IN SOA @ rname.invalid. ( 2 ; serial 1M ; refresh 1M ; retry 1M ; expire 3H ) ; minimum @ NS ns1 @ NS ns2 ns1 A 10.0.0.182 ns2 A 10.0.0.115 * A 10.0.0.184
從slave上的配置
cat /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 Administrator's Reference Manual (ARM) for details about the // configuration located in /usr/share/doc/bind-{version}/Bv9ARM.html options { listen-on port 53 { any; }; 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; bindkeys-file "/etc/named/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; }; }; zone "." IN { type hint; file "named.ca"; }; #include "/etc/named/named.rfc1912.zones"; include "/etc/named/named.sx.zones"; include "/etc/named/named.root.key";
cat /etc/named/named.sx.zones
注意自定義文件屬組和屬主
zone "sx" IN { type slave; masters { 10.0.0.182; }; file "slaves/sx.zone"; }; zone "sx.com" IN { type slave; masters { 10.0.0.182; }; file "slaves/sx.com.zone"; };
3、啟動(主備上分別操作)
systemctl start named
systemctl enable named
備上啟動后,配置文件會自動同步過來
啟動成功標識包含進程和端口

4、主從測試
在主上編輯zone配置文件
每次執行完之后serial 值增加1
然后主上執行systectl restart named
在備機上驗證配置是否同步過來
先看備機上的日志,tail -n 100 /var/log/message,正常同步會有如下類似提示日志信息
在看配置文件
cat /var/named/slaves/sx.com.zone ,看到配置已經同步,serial 值也同步變更過來

5、客戶端配置解析測試
在內網的其他機器上配置/etc/resolv.conf 添加該dns
然后進行解析對應域名,可以正常解析
echo "nameserver 10.0.0.115" >> /etc/resolv.conf

配置調試過程中問題總結:
問題一:
配置完成后備機上zone同步過來的顯示的亂碼文件
主要原因:主從解析文件類型不同
解析方法:
從服務器配置文件(/etc/named.conf )添加並重啟服務
masterfile-format text ;
問題二:
配置完成后發現不會自動主從同步
主從同步配置需要添加如下配置
主上需要配置通知服務開啟(/etc/named.conf ),添加如下配置
notify yes;
在該配置文件上添加如下內容/etc/named/named.sx.zones
also-notify { 10.0.0.115; }; #配置備機的IP
allow-transfer { 10.0.0.115; }; #允許備機進行同步數據,同步刷新時間間隔根據zone配置的refresh的時間,進行刷新