34.5. Master / Slave

34.5.1. master /etc/named.conf

# cat /etc/named.conf

        zone "example.com" {
                type master;
                file "/var/named/example.com.zone";
                allow-transfer { 172.16.1.23; 120.100.100.23; };
        };
			

notify 指令会自动通知所有这个域的所有在ns记录上的机器，also-notify指令可以用来通知所有不在ns记录上的dns服务器

        zone "example.com" {
                type master;
                file "example.com.zone";
                allow-transfer { 172.16.1.23; };
                notify yes;
                also-notify { 172.16.1.23; };
        };

		zone "1.16.172.in-addr.arpa" IN {
			type master;
			file "1.16.172";
			allow-transfer { 172.16.1.23 ; };
			notify yes;
			also-notify { 172.16.1.23 ; };
		};
        zone "144.132.102.in-addr.arpa" IN {
			type master;
			file "144.132.102.in-addr.arpa.zone";
			allow-transfer { 172.16.1.23 ; };
			notify yes;
			also-notify { 172.16.1.23 ; };
         };

34.5.1.1. /var/named/example.com.zone

# cat 144.132.102.in-addr.arpa.zone
$TTL    86400
@       IN      SOA     localhost. root.localhost.  (
                                      2010010100 ; Serial
                                      28800      ; Refresh
                                      14400      ; Retry
                                      3600000    ; Expire
                                      86400 )    ; Minimum
        IN      NS      ns1.example.com.

6       IN      PTR     www.example.com.
15      IN      PTR     bbs.example.com.
19      IN      PTR     images.example.com.
				

34.5.1.2. /var/named/example.com.zone

$TTL    86400
@               IN SOA  example.com. root.example.com. (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum
                IN NS           ns1.example.com.
                IN NS           ns2.example.com.
@               IN A 120.100.100.6
@               IN MX 10 mx.corpease.net.

ns1             IN A 120.100.100.20
ns2             IN A 120.100.100.23
www            IN A 120.100.100.6
images         IN A 120.100.100.6
				

34.5.2. slave /etc/named.conf

        zone "example.com" {
                type slave;
                file "/var/named/slaves/example.com.zone";
                masters { 172.16.1.20; 120.100.100.20; };
        };
			

        zone "144.132.120.in-addr.arpa" IN {
                type slave;
                file "slaves/144.132.120.in-addr.arpa.zone";
                masters { 172.16.1.20; };
        };
			

34.5.3. FAQ

34.5.3.1. Master 更改后 Slave 不同步

采用 master / slave 结构的DNS服务器，一般情况下只需要维护master上的记录即可

很多人会遇到，档你在master 增加一个记录后 slave 没有更新，删除slave 上的zone 文件 restart 才能更新。

这是因为你没有更改 2010010100 ; Serial 这项。凡是对zone文件操作后必须更改Serial建议使用日期与时间作为该值。

另外Serial 的新数值必须大于就数值才能更新

34.5.3.2. Master 与 Slave 的 Test

启动主DNS服务器然后测试解析与反向解析，然后启动备份DNS，观察复制情况，再测试正向与反向解析。

dig @120.100.100.20 www.example.com
				

$ dig @120.100.100.20 -x 120.100.100.6

; <<>> DiG 9.7.3 <<>> @120.100.100.20 -x 120.100.100.6
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 41279
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;6.144.132.120.in-addr.arpa.    IN      PTR

;; ANSWER SECTION:
6.144.132.120.in-addr.arpa. 86400 IN    PTR     www.example.com.

;; AUTHORITY SECTION:
144.132.120.in-addr.arpa. 86400 IN      NS      ns1.example.com.

;; ADDITIONAL SECTION:
ns1.example.com.            1800    IN      A       120.100.100.20

;; Query time: 6 msec
;; SERVER: 120.100.100.20#53(120.100.100.20)
;; WHEN: Wed Feb  8 10:37:28 2012
;; MSG SIZE  rcvd: 103

neo@neo-OptiPlex-380:~$ dig @120.100.100.20 -x 120.100.100.19

; <<>> DiG 9.7.3 <<>> @120.100.100.20 -x 120.100.100.19
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 17336
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 1

;; QUESTION SECTION:
;19.144.132.120.in-addr.arpa.   IN      PTR

;; ANSWER SECTION:
19.144.132.120.in-addr.arpa. 86400 IN   PTR     images.example.com.

;; AUTHORITY SECTION:
144.132.120.in-addr.arpa. 86400 IN      NS      ns1.example.com.

;; ADDITIONAL SECTION:
ns1.example.com.            1800    IN      A       120.100.100.20

;; Query time: 6 msec
;; SERVER: 120.100.100.20#53(120.100.100.20)
;; WHEN: Wed Feb  8 10:37:39 2012
;; MSG SIZE  rcvd: 107

原文出处：Netkiller 系列 手札
本文作者：陈景峯
转载请与作者联系，同时请务必标明文章原始出处和作者信息及本声明。