linux命令：DNS域名解析,bind

时间：2017-01-09 16:59:15 收藏：0 阅读：1872

DNS：Domain Name Service 域名服务

DNS服务器的软件bind:berkeley internet name domain

named-checkconf：检查配置文件是否有语法错误命令

named-checkzone：检查区域文件是否有语法错误命令

dig：domain information groper

dig -t NS . 查找根域的所有DNS服务器

bind97：
   /etc/named.conf 主配置文件
       BIND进程的工作属性
       区域的定义
   /etc/rndc.key
       rndc: Remote Name Domain Controller
       密钥文件
       配置信息：/etc/rndc.conf

   /var/named/    区域数据文件
/etc/rc.d/init.d/named    {start|stop|restart|status|reload}

   二进制程序：named
bind-chroot:
   默认：named
       用户：named
       组：named

/var/named/chroot/
       etc/named.conf
       etc/rdnc.key
       sbin/named
       var/named/

[root@test ~]# yum list all |grep bind
This system is not registered with RHN.
RHN support will be disabled.
bind-libs.i386 30:9.3.6-4.P1.el5 installed
bind-utils.i386 30:9.3.6-4.P1.el5 installed

[root@test ~]# rpm -e bind-libs bind-utils #rpm -e 卸载软件包
[root@test ~]# yum list all |grep bind
This system is not registered with RHN.
RHN support will be disabled.
bind.i386 30:9.3.6-4.P1.el5 Media
bind-chroot.i386 30:9.3.6-4.P1.el5 Media

一、bind安装

bind97下载地址：http://mirrors.ctyun.cn/centos/5/os/i386/CentOS/

[root@johntest ~]# rpm -ivh bind97-libs-9.7.0-21.P2.el5.i386.rpm
warning: bind97-libs-9.7.0-21.P2.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID e8562897
Preparing... ################################### [100%]
1:bind97-libs ################################# [100%]

[root@johntest ~]# bind97-utils-9.7.0-21.P2.el5.i386.rpm
warning: bind97-utils-9.7.0-21.P2.el5.i386.rpm: Header V3 DSA signature: NOKEY, key ID e8562897
Preparing... ############################## [100%]
1:bind97-utils ############################ [100%]

[root@johntest ~]# rpm -ivh bind97-9.7.0-21.P2.el5.x86_64.rpm

warning: bind97-9.7.0-21.P2.el5.x86_64.rpm: Header V3 DSA signature: NOKEY, key ID e8562897

Preparing... ########################################### [100%]

1:bind97 ########################################### [100%]

二、语法错误判断、日志查看、服务启动状态

[root@johntest etc]# vi named.conf
options {
   directory   "/var/named";
};

zone "." IN {
   type hint;
   file "named.ca";
};

zone "localhost" IN {
   type master;
   file "named.localhost";
};

zone "0.0.127.in-addr.arpa" IN {
   type master;
   file "named.loopback";
};

[root@johntest etc]# named-checkconf 检查named.conf配置文件是否有语法错误

[root@johntest etc]# named-checkzone "." /var/named/named.ca 检查区域文件是否有语法错误
zone ./IN: has 0 SOA records
zone ./IN: not loaded due to errors.
[root@johntest etc]# named-checkzone "localhost" /var/named/named.localhost
zone localhost/IN: loaded serial 0
OK
[root@johntest etc]# named-checkzone "0.0.127.in-addr.arpa" /var/named/named.loopback
zone 0.0.127.in-addr.arpa/IN: loaded serial 0
OK

[root@johntest etc]# vim /etc/selinux/config #启动服务器需把selinux关闭才能启动

# enforcing - SELinux security policy is enforced.

# permissive - SELinux prints warnings instead of enforcing.

# disabled - SELinux is fully disabled.

SELINUX=permissive #默认为enforcing 需关闭掉，设置为permissive，否则无法启动

[root@johntest etc]# service named start
Starting named: named: already running                     [ OK ]
[root@test etc]# service named restart
Stopping named: .                                          [ OK ]
Starting named:                                            [ OK ]
[root@johntest etc]# tail /var/log/messages
Dec 13 15:37:16 test named[29856]: command channel listening on 127.0.0.1#953
Dec 13 15:37:16 test named[29856]: zone 0.0.127.in-addr.arpa/IN: loaded serial 0
Dec 13 15:37:16 test named[29856]: zone localhost/IN: loaded serial 0
Dec 13 15:37:16 test named[29856]: running

[root@johntest ~]# vi /etc/resolv.conf
nameserver 110.19.131.131
search localdomain

[root@johntest ~]# dig -t NS .

; <<>> DiG 9.7.0-P2-RedHat-9.7.0-21.P2.el5 <<>> -t NS .
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 6718
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 12
;; QUESTION SECTION:
;.               IN   NS
;; ANSWER SECTION:
.           16803   IN   NS   i.root-servers.net.
.           16803   IN   NS   a.root-servers.net.
.           16803   IN   NS   e.root-servers.net.
.           16803   IN   NS   k.root-servers.net.
.           16803   IN   NS   d.root-servers.net.
.           16803   IN   NS   b.root-servers.net.
.           16803   IN   NS   g.root-servers.net.
.           16803   IN   NS   c.root-servers.net.
.           16803   IN   NS   l.root-servers.net.
.           16803   IN   NS   h.root-servers.net.
.           16803   IN   NS   f.root-servers.net.
.           16803   IN   NS   j.root-servers.net.
.           16803   IN   NS   m.root-servers.net.
;; ADDITIONAL SECTION:
i.root-servers.net.   86400   IN   A   192.36.148.17
i.root-servers.net.   17019   IN   AAAA   2001:7fe::53
a.root-servers.net.   17019   IN   A   198.41.0.4
a.root-servers.net.   17019   IN   AAAA   2001:503:ba3e::2:30
e.root-servers.net.   29300   IN   A   192.203.230.10
e.root-servers.net.   86400   IN   AAAA   2001:500:a8::e
k.root-servers.net.   29300   IN   A   193.0.14.129
k.root-servers.net.   17019   IN   AAAA   2001:7fd::1
d.root-servers.net.   29300   IN   A   199.7.91.13
d.root-servers.net.   17019   IN   AAAA   2001:500:2d::d
b.root-servers.net.   16803   IN   A   192.228.79.201
b.root-servers.net.   17019   IN   AAAA   2001:500:84::b
;; Query time: 38 msec
;; SERVER: 10.109.131.131#53(10.109.131.131)
;; WHEN: Wed Dec 14 08:14:20 2016
;; MSG SIZE rcvd: 505
[root@johntest ~]# ping www.163.com
PING 163.xdwscache.ourglb0.com (113.107.57.41) 56(84) bytes of data.
64 bytes from 113.107.57.41: icmp_seq=1 ttl=53 time=39.4 ms
64 bytes from 113.107.57.41: icmp_seq=2 ttl=53 time=38.3 ms
--- 163.xdwscache.ourglb0.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1013ms
rtt min/avg/max/mdev = 38.381/38.924/39.468/0.578 ms

[root@johntest ~]# chkconfig --list named
named 0:off 1:off 2:off 3:off 4:off 5:off 6:off
[root@test ~]# chkconfig named on
[root@test ~]# chkconfig --list named
named 0:off 1:off 2:on 3:on 4:on 5:on 6:off
[root@test ~]#

三、创建本地NS正向域

[root@johntest ~]# vi /etc/named.conf

... #新增以下部分

zone "johntest.com" IN {
type master;
file "johntest.com.zone";
};

[root@johntest etc]# chown root:named named.conf #修改用户和组

[root@johntest ~]# named-checkconf /etc/named.conf #检查named.conf配置文件是否有语法错误
/etc/named.conf:24: missing ‘;‘ before end of file

[root@johntest named]# vi johntest.com.zone #正向区域名称

$TTL 600   #宏要加$
johntest.com.   IN SOA     ns1.johntest.com.    admin.johntest.com. (
20161214 #系列号
     1H #刷新时间
       5M #重试时间
    2D #过期时间
      6H ) #否定TTL值时间（需用括号括起来）
johntest.com.   IN      NS      ns1.johntest.com.
     IN      MX  10 mail   #域名可省，10为邮件等级
ns1         IN      A      10.109.131.131
mail        IN      A 10.109.131.120
www        IN      A       10.109.131.201
www       IN      A 10.109.131.232
ftp   IN      CNAME   www

[root@johntest named]# chown root:named johntest.com.zone
[root@johntest named]# l

总计 8

-rw-r--r-- 1 root named 471 01-09 04:16 johntest.com.zone

四、语创建本地NS反向域

[root@johntest ~]# vi /etc/named.conf

... #新增以下部分

zone "1.168.192.in-addr.arpa" IN {
type master;
file "192.168.1.zone";
};

[root@johntest named]# cp -p johntest.com.zone 192.168.1.zone #将正向复制为反向区域名称

[root@johntest named]# vi johntest.com.zone #修改反向区域名称

$TTL 600   #宏要加$
@   IN   SOA   ns1.johntest.com. admin.johntest.com. (
                                20161214
                                1H
                                5M
                                2D
                                6H )

IN NS ns1.johntest.com. // 最后一项必须是完整的记录，句尾不可忘记写上" . "

3 IN PTR ns1.johntest.com.

3 IN PTR www.johntest.com.

4 IN PTR mail.johntest.com.

5 IN PTR www.johntest.com.

dig -x 192.168.1.3

dig -x 192.168.1.4

dig +norecurse -t A www.163.com @192.168.1.3 #不递归查询

dig +trace -t A www.baidu.com @192.168.1.3 #递归显示查询结果

五、更改配制文件后即可限定查询段

[root@johntest etc]# vi named.conf
options {
directory "/var/named";

allow-recursion { 192.168.1.0/24; }; //只允许此IP段递归查询

};

zone "." IN {
   type hint;
   file "named.ca";
};

zone "localhost" IN {
   type master;
   file "named.localhost";
   allow-transfer { none; };     //none不允许所有客户端发出传送请求
};

zone "0.0.127.in-addr.arpa" IN {
   type master;
   file "named.loopback";
   allow-transfer { none; };
};

zone "jacktest.com" IN {
        type master;
        file "jacktest.com.zone";
   allow-transfer { 192.168.1.5; };    //只允许此IP发出传送请求
};

zone "1.168.192.in-addr.arpa" IN {
   type master;
   file "192.168.1.zone";
   allow-transfer { 192.168.1.5; };
};

[root@johntest etc]# tail /var/log/messages
Dec 15 14:11:41 test named[7276]: zone 1.168.192.in-addr.arpa/IN: loaded serial 2016121401
Dec 15 14:11:41 test named[7276]: zone jacktest.com/IN: loaded serial 20161214
Dec 15 14:11:41 test named[7276]: zone localhost/IN: loaded serial 0
Dec 15 14:11:41 test named[7276]: running
Dec 15 14:13:31 test named[7276]: client 192.168.1.5#58423: transfer of ‘jacktest.com/IN‘: AXFR started
Dec 15 14:13:31 test named[7276]: client 192.168.1.5#58423: transfer of ‘jacktest.com/IN‘: AXFR ended

六、设置从DNS服务器

[root@jacktest named]# setenforce 0
setenforce: SELinux is disabled

[root@jacktest named]# scp 192.168.1.3:/etc/named.conf /etc/
The authenticity of host ‘192.168.1.3 (192.168.1.3)‘ can‘t be established.
RSA key fingerprint is c2:f2:75:5c:ab:4a:43:d3:e1:76:bc:d2:0f:c7:d6:32.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added ‘192.168.1.3‘ (RSA) to the list of known hosts.
root@192.168.1.3‘s password:
named.conf

[root@johntest etc]# vi /etc/named.conf

...

zone "jacktest.com" IN {
        type slave;
        file "slaves/jacktest.com.zone";
        allow-transfer { 192.168.1.5; };
};

zone "1.168.192.in-addr.arpa" IN {
        type slave;
        file "slaves/192.168.1.zone";
        allow-transfer { 192.168.1.5; };
};

验证：

[root@johntest slaves]# tail /var/log/messages    #192.168.1.3主
Dec 15 15:43:35 test named[7595]: zone 1.168.192.in-addr.arpa/IN: loaded serial 2016121401
Dec 15 15:43:35 test named[7595]: zone jacktest.com/IN: loaded serial 20161214
Dec 15 15:43:35 test named[7595]: zone localhost/IN: loaded serial 0
Dec 15 15:43:35 test named[7595]: running
Dec 15 15:44:12 test named[7595]: client 192.168.1.5#47432: transfer of ‘jacktest.com/IN‘: AXFR started
Dec 15 15:44:12 test named[7595]: client 192.168.1.5#47432: transfer of ‘jacktest.com/IN‘: AXFR ended
Dec 15 17:25:29 test named[7595]: client 192.168.1.5#34268: transfer of ‘jacktest.com/IN‘: AXFR started
Dec 15 17:25:29 test named[7595]: client 192.168.1.5#34268: transfer of ‘jacktest.com/IN‘: AXFR ended
Dec 15 17:25:29 test named[7595]: client 192.168.1.5#59389: transfer of ‘1.168.192.in-addr.arpa/IN‘: AXFR started    #传送开始
Dec 15 17:25:29 test named[7595]: client 192.168.1.5#59389: transfer of ‘1.168.192.in-addr.arpa/IN‘: AXFR ended   #传送结果

[root@johntest named]# tail /var/log/messages #192.168.1.5
Dec 15 17:28:13 jacktest named[10089]: zone localhost/IN: loaded serial 0
Dec 15 17:28:13 jacktest named[10089]: running
Dec 15 17:28:13 jacktest named[10089]: zone jacktest.com/IN: Transfer started.
Dec 15 17:28:13 jacktest named[10089]: transfer of ‘jacktest.com/IN‘ from 192.168.1.3#53: connected using 192.168.1.5#34268
Dec 15 17:28:13 jacktest named[10089]: zone jacktest.com/IN: transferred serial 20161214
Dec 15 17:28:13 jacktest named[10089]: transfer of ‘jacktest.com/IN‘ from 192.168.1.3#53: Transfer completed: 1 messages, 9 records, 233 bytes, 0.004 secs (58250 bytes/sec)
Dec 15 17:28:13 jacktest named[10089]: zone 1.168.192.in-addr.arpa/IN: Transfer started.
Dec 15 17:28:13 jacktest named[10089]: transfer of ‘1.168.192.in-addr.arpa/IN‘ from 192.168.1.3#53: connected using 192.168.1.5#59389
Dec 15 17:28:13 jacktest named[10089]: zone 1.168.192.in-addr.arpa/IN: transferred serial 2016121401
Dec 15 17:28:13 jacktest named[10089]: transfer of ‘1.168.192.in-addr.arpa/IN‘ from 192.168.1.3#53: Transfer completed: 1 messages, 7 records, 219 bytes, 0.002 secs (109500 bytes/sec)

七、测试NS自动更新到从服务器

[root@johntest named]# vi jacktest.com.zone    #192.168.1.3主
$TTL 600
jacktest.com.   IN   SOA   ns1.jacktest.com.   admin.jacktest.com. (
     2016121404     #3改成4
...
imap       IN   A   192.168.1.6

haha        IN   A   192.168.1.7    #新增一条记录
[root@test named]# service named reload
Reloading named:                                           [ OK ]
[root@johntest named]# tail /var/log/messages    #192.168.1.3主NS
Dec 16 10:05:53 test named[10112]: reloading configuration succeeded
Dec 16 10:05:53 test named[10112]: reloading zones succeeded
Dec 16 10:05:53 test named[10112]: zone jacktest.com/IN: loaded serial 2016121404
Dec 16 10:05:53 test named[10112]: zone jacktest.com/IN: sending notifies (serial 2016121404)
Dec 16 10:05:53 test named[10112]: client 192.168.1.5#50038: transfer of ‘jacktest.com/IN‘: AXFR-style IXFR started
Dec 16 10:05:53 test named[10112]: client 192.168.1.5#50038: transfer of ‘jacktest.com/IN‘: AXFR-style IXFR ended
[root@johntest named]# tail /var/log/messages    #192.168.1.5从NS
Dec 16 10:08:38 jacktest named[12536]: client 192.168.1.3#6791: received notify for zone ‘jacktest.com‘
Dec 16 10:08:38 jacktest named[12536]: zone jacktest.com/IN: Transfer started.
Dec 16 10:08:38 jacktest named[12536]: transfer of ‘jacktest.com/IN‘ from 192.168.1.3#53: connected using 192.168.1.5#50038
Dec 16 10:08:38 jacktest named[12536]: zone jacktest.com/IN: transferred serial 2016121404
Dec 16 10:08:38 jacktest named[12536]: transfer of ‘jacktest.com/IN‘ from 192.168.1.3#53: Transfer completed: 1 messages, 13 records, 309 bytes, 0.002 secs (154500 bytes/sec)
Dec 16 10:08:38 jacktest named[12536]: zone jacktest.com/IN: sending notifies (serial 2016121404)

[root@johntest slaves]# cat jacktest.com.zone     #192.168.1.5从NS
jacktest.com IN SOA   ns1.jacktest.com. admin.jacktest.com. (
         2016121404 ; serial
...
ftp       CNAME   www
haha       A   192.168.1.7    #自动学习成功

八、开放远程访问DC

Remote Name Daemon Control # [di:mn]守护进程

[root@johntest ~]# rndc-confgen > /etc/rndc.conf
[root@johntest ~]# cat /etc/rndc.conf
# Start of rndc.conf
key "rndc-key" {
   algorithm hmac-md5;
   secret "PElKGniJbHk/esQ9zpN+xg==";
};
options {
   default-key "rndc-key";
   default-server 127.0.0.1;
   default-port 953;
};
# End of rndc.conf
# Use with the following in named.conf, adjusting the allow list as needed:
# key "rndc-key" {
#    algorithm hmac-md5;
#    secret "PElKGniJbHk/esQ9zpN+xg==";
# };
#
# controls {
#    inet 127.0.0.1 port 953
#        allow { 127.0.0.1; } keys { "rndc-key"; };
# };
# End of named.conf    #绿色部分复制添加到named.conf
[root@johntest ~]# rndc -c /etc/rndc.conf status
rndc: connection to remote host closed
This may indicate that
* the remote server is using an older version of the command protocol,
* this host is not authorized to connect,
* the clocks are not synchronized, or
* the key is invalid.
[root@johntest ~]# rm /etc/rndc.key
rm: remove regular file `/etc/rndc.key‘? y
[root@test ~]# rndc -c /etc/rndc.conf status
rndc: connection to remote host closed
This may indicate that
* the remote server is using an older version of the command protocol,
* this host is not authorized to connect,
* the clocks are not synchronized, or
* the key is invalid.
[root@test ~]# service named restart
Stopping named: .                  [ OK ]
Generating /etc/rndc.key:                 [ OK ]
Starting named:                     [ OK ]
[root@johntest ~]# rndc -c /etc/rndc.conf status
version: 9.7.0-P2-RedHat-9.7.0-21.P2.el5
CPUs found: 8
worker threads: 8
number of zones: 16
debug level: 0
xfers running: 0
xfers deferred: 0
soa queries in progress: 0
query logging is OFF
recursive clients: 0/0/1000
tcp clients: 0/100
server is up and running
[root@johntest ~]# rndc -c /etc/rndc.conf notify "jacktest.com"
zone notify queued
[root@johntest ~]# tail /var/log/messages
Dec 16 10:36:32 test named[10285]: received control channel command ‘notify jacktest.com‘
Dec 16 10:36:32 test named[10285]: zone jacktest.com/IN: sending notifies (serial 2016121404)
[root@test ~]# rndc -c /etc/rndc.conf flush

[root@test ~]# rndc -c /etc/rndc.conf stop

...

controls {
inet 192.168.1.3 port 953 #监听地址
allow { 192.168.1.5; } keys { "rndc-key"; }; #允许访问192.168.1.3的IP
};

[root@johntest ~]# scp /etc/rndc.conf 192.168.1.5:/root/

[root@johntest ~]# vi /etc/rndc.conf #192.168.1.5从NS

# Start of rndc.conf
key "rndc-key" {
        algorithm hmac-md5;
        secret "PElKGniJbHk/esQ9zpN+xg==";
};

options {
        default-key "rndc-key";
        default-server 192.168.1.3;
        default-port 953;
};

[root@johntest ~]# rndc -c rndc.conf status #192.168.1.5从NS，已可远程访问
version: 9.7.0-P2-RedHat-9.7.0-21.P2.el5 #一般不开放远程允许访问，非常危险
CPUs found: 8
worker threads: 8
number of zones: 16
debug level: 0
xfers running: 0
xfers deferred: 0
soa queries in progress: 0
query logging is OFF
recursive clients: 0/0/1000
tcp clients: 0/100
server is up and running

[root@test ~]#

九、子域及子域转发（forward）

forward {only|first}
forwarders {};
zone "ZONE_NAME" IN {
   type forward;
   forward first;
    forwarders {172.168.1.3};

};

新增子域服务器192.168.1.8

[root@test2 ~]# vi fin.jacktest.com.zone #192.168.1.8 子DNS

$TTL 600     ; 10 minutes
@ IN SOA ns1.fin.jacktest.com. admin.fin.jacktest.com. (
                      2016121701 ; serial
                      3600       ; refresh (1 hour)
                      300        ; retry (5 minutes)
                     172800     ; expire (2 days)
                      21600      ; minimum (6 hours)
                       )
          NS      ns1.fin.jacktest.com.
           MX      10 mail.fin.jacktest.com.
ns1           A       192.168.1.8
mail         A       192.168.1.9
www        A       192.168.1.10

[root@test2 ~]# service named restart
Stopping named: . [ OK ]
Starting named: [ OK ]

验证子域

[root@johntest named]# dig -t A ns1.fin.jacktest.com @192.168.1.3  #通过主域可解析子域IP

; <<>> DiG 9.7.0-P2-RedHat-9.7.0-21.P2.el5 <<>> -t A ns1.fin.jacktest.com @192.168.1.3
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57664
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;ns1.fin.jacktest.com.      IN   A

;; ANSWER SECTION:
ns1.fin.jacktest.com.   600   IN   A   192.168.1.8

;; AUTHORITY SECTION:
fin.jacktest.com.   600   IN   NS   ns1.fin.jacktest.com.

;; Query time: 3 msec
;; SERVER: 192.168.1.3#53(192.168.1.3)
;; WHEN: Sat Dec 17 11:11:13 2016
;; MSG SIZE rcvd: 68

[root@johntest named]# dig -t A ns1.fin.jacktest.com @192.168.1.8   #通过子域可解析子域IP

; <<>> DiG 9.7.0-P2-RedHat-9.7.0-21.P2.el5 <<>> -t A ns1.fin.jacktest.com @192.168.1.8
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53646
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0

;; QUESTION SECTION:
;ns1.fin.jacktest.com.    IN   A

;; ANSWER SECTION:
ns1.fin.jacktest.com.   600   IN   A   192.168.1.8

;; AUTHORITY SECTION:
fin.jacktest.com.   600   IN   NS   ns1.fin.jacktest.com.

;; Query time: 2 msec
;; SERVER: 192.168.1.8#53(192.168.1.8)
;; WHEN: Sat Dec 17 11:12:39 2016
;; MSG SIZE rcvd: 68

[root@johntest named]# nslookup
> server 192.168.1.3
Default server: 192.168.1.3
Address: 192.168.1.3#53
> set q=A
> www.jacktest.com
Server:       192.168.1.3      #通过服务器192.168.1.3查找
Address:   192.168.1.3#53
Name:   www.jacktest.com      #查找出两条记录
Address: 192.168.1.3
Name:   www.jacktest.com
Address: 192.168.1.5
> set q=A
> www.fin.jacktest.com
Server:       192.168.1.3     #通过此服务器查找
Address:   192.168.1.3#53
Non-authoritative answer:     #查找出一条记录，有为非官方记录
Name:   www.fin.jacktest.com
Address: 192.168.1.10
> server 192.168.1.8
Default server: 192.168.1.8
Address: 192.168.1.8#53
> set q=A
> www.fin.jacktest.com
Server:       192.168.1.8     #通过服务器192.168.1.8查找
Address:   192.168.1.8#53

Name:   www.fin.jacktest.com     #查找出一条记录
Address: 192.168.1.10
> set q=A
> www.jacktest.com    #通过子域服务器192.168.1.8查找父域的A记录
Server:       192.168.1.8
Address:   192.168.1.8#53

** server can‘t find www.jacktest.com.localdomain: SERVFAIL    #子域无法查找父域的A记录
>

默认子域无法查找父域信息，定义转发即可告诉子域

[root@jacktest2 ~]# vi /etc/rndc.conf #192.168.1.8 子DNS 中新增以下部分

zone "jacktest.com" IN {
        type forward;
        forward first;
        forwarders { 192.168.1.3; };
};

验证：

[root@test named]# nslookup

> set q=A
> www.jacktest.com
Server:       192.168.1.8     #通过服务器192.168.1.8查找
Address:   192.168.1.8#53
Non-authoritative answer:
Name:   www.jacktest.com    #新增forward后查找出两条记录
Address: 192.168.1.5
Name:   www.jacktest.com
Address: 192.168.1.3

本文出自 “学linux历程” 博客，请务必保留此出处http://woyaoxuelinux.blog.51cto.com/5663865/1890312