domain-name-system – 如何为内部DNS服务器正确配置BIND转发区域？

我有：

>内部DNS服务器ns1.internal,IP 192.168.0.4.
>具有外部TLD mydns.example.com和内部IP 192.168.0.5的外部DNS服务器.它可以从Internet(通过静态NAT规则)和本地网络访问.

我正在尝试设置外部DNS服务器以将区域subzone.mydns.example.com转发到内部DNS服务器.内部DNS服务器对此区域具有权威性.

重要提示：我无法修改内部DNS服务器配置.但是,如果需要诊断问题,我可以阅读它.

外部DNS服务器上的文件/etc/named.conf：

options {
  directory "/var/named";
  version "get lost";

  recursion yes;
  allow-transfer {"none";};
  allow-query { any; };
  allow-recursion { any; };
};

logging{
  channel example_log{
   file "/var/log/named/named.log" versions 3 size 2m;
   severity info;
   print-severity yes;
   print-time yes;
   print-category yes;
 };
 category default{
  example_log;
 };
};

// Zones:

zone "mydns.example.com" {
  type master;
  file "mydns.example.com.zone";
  allow-update{none;};
};

zone "subzone.mydns.example.com" {
  type forward;
  forwarders { 192.168.0.4; };
};

外部DNS服务器上的文件/var/named/mydns.example.com.zone：

$TTL 1
$ORIGIN mydns.example.com.
@             IN      SOA   mydns.example.com. root.mydns.example.com. (
                        2003080800 ; se = serial number
                        60         ; ref = refresh
                        60         ; ret = update retry
                        60         ; ex = expiry
                        60         ; min = minimum
                        )

@             IN      NS      mydns.example.com.

所以,现在我尝试解决一些DNS记录.
外部服务器区似乎工作.

workstation$dig mydns.example.com NS +tcp +short
mydns.example.com.

但转发区域不起作用：

workstation$dig subzone.mydns.example.com NS +tcp

; <<>> DiG 9.8.1-P1 <<>> subzone.mydns.example.com NS +tcp
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY,status: NXDOMAIN,id: 36887
;; flags: qr rd ra; QUERY: 1,ANSWER: 0,AUTHORITY: 1,ADDITIONAL: 0

;; QUESTION SECTION:
;subzone.mydns.example.com.        IN      NS

;; AUTHORITY SECTION:
mydns.example.com.    1       IN      SOA     mydns.example.com. root.mydns.example.com. 2003080800 60 60 60 60

;; Query time: 3 msec
;; SERVER: 91.144.182.3#53(91.144.182.3)
;; WHEN: Thu Jul 19 17:27:54 2012
;; MSG SIZE  rcvd: 108

在远程Internet主机和内部主机上执行这些命令时,结果完全相同.

如果我尝试解析subzone.mydns.example.com.从外部名称服务器和显式指定内部服务器,我得到：

mydns$dig @192.168.0.4 subzone.mydns.example.com NS

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-16.P1.el5 <<>> @192.168.0.4 subzone.mydns.example.com NS
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY,status: NOERROR,id: 87
;; flags: qr aa rd; QUERY: 1,ANSWER: 3,AUTHORITY: 0,ADDITIONAL: 3

;; QUESTION SECTION:
;subzone.mydns.example.com.        IN      NS

;; ANSWER SECTION:
subzone.mydns.example.com. 3600 IN NS      ns1.internal.

;; ADDITIONAL SECTION:
ns1.internal.      3600    IN      A       192.168.0.4

;; Query time: 613 msec
;; SERVER: 192.168.0.4#53(192.168.0.4)
;; WHEN: Thu Jul 19 18:20:55 2012
;; MSG SIZE  rcvd: 163

怎么了？如何配置转发DNS区域按预期工作？

解决方法

添加’仅向前;’转发区域的声明：

zone "subzone.mydns.example.com" {
    type forward;
    forward only;
    forwarders { 192.168.0.4; };
};