Ubuntu Linux：Bind双重域名配置

相信现在有不少地方都是起双重DNS的，即对外解析成公网地址，对内解析成内网地址。一般的做法是用两台DNS服务器分开来做的，但如果机器紧张，只有一台的话或出于安全考虑只用一台的话，其实也是可以做的，具体作法可以分以下两种情况： 使用Bind8和Bind9的做法是不一样的， Bind8下的实现方法在DNS服务器上运行两个BIND，分别为来自内部网络和外部网络的域名请求提供解析，每个BIND具有不同的配置文件和域名数据库文件，并分别在不同的端口监听。DNS服务器在接到客户端请求时，根据客户的IP地址将请求重定向到不同的BIND服务端口，这样就可以根据客户端的IP地址将不同的解析结果返回给客户端，而整个过程对于客户端来说都是透明的。实现的关键在于运行两个BIND及运用iptables命令进行IP地址及端口改写操作。 具体配置的话： 在/etc/下生成两个named配置文件named.in与named.out named.in

## named.conf - configuration for bind(named.in)

#

# Generated automatically by redhat-config-bind, alchemist et al.

# Any changes not supported by redhat-config-bind should be put

# in /etc/named.custom

#

include "/etc/named.custom";

include "/etc/rndc.key";

options {

directory "/var/named_in/";

datasize 2098;

......

};

};

#Log Files

logging {

category queries {

default_syslog;

};

};

#DataBase Files

zone "0.0.127.in-addr.arpa" {

type master;

file "0.0.127.in-addr.arpa.zone";

};

zone "10.in-addr.arpa" {

type master;

file "10.in-addr.arpa.zone";

};

zone "localhost" {

type master;

file "localhost.zone";

};

zone "xxu.edu.cn" {

type master;

file "xxu.edu.cn.zone";

};

named.out

## named.conf - configuration for bind(named.out)

#

# Generated automatically by redhat-config-bind, alchemist et al.

# Any changes not supported by redhat-config-bind should be put

# in /etc/named.custom

#

include "/etc/named.custom";

include "/etc/rndc.key";

options {

directory "/var/named_out/";

datasize 2098;

... ...

};

# 注意这里监听的端口不一样了

listen-on port 8053 {

# 本机IP地址

10.xx.xx.xx;

};

};

#Log Files

logging {

category queries {

default_syslog;

};

};

#DataBase Files

zone "0.0.127.in-addr.arpa" {

type master;

file "0.0.127.in-addr.arpa.zone";

};

zone "xx.xx.210.in-addr.arpa" {

type master;

file "xx.xx.210.in-addr.arpa.zone";

};

zone "localhost" {

type master;

file "localhost.zone";

};

zone "xxu.edu.cn" {

type master;

file "xxu.edu.cn.zone";

};

为什么选对外发布的做重定向呢，当时的考虑是对内解析的流量大，可以减少一个环节。

然后做iptables的重定向，在iptable配置文件中添加

-A PREROUTING -s ! 10.0.0.0/255.0.0.0 -i eth0 -p udp -m udp --dport 53 -j REDIRECT --to-ports 8053

-A POSTROUTING -o eth0 -p udp -m udp --sport 8053 -j SNAT --to-source 10.xx.xx.xx:53

COMMIT

最后在做一个启动脚本：

#!/bin/sh

echo "Enabling IP Forwarding ..."

echo 1 > /proc/sys/net/ipv4/ip_forward

echo "Enabling DNS(outside) Service ..."

/usr/sbin/named -u named -c /etc/named.out

echo "Enabling DNS(inside) Service ..."

/usr/sbin/named -u named -c /etc/named.in

重启机器就OK了！

Bind9 下的实现方法

只需要一个named.conf文件就搞定 具体配置：

include "/etc/rndc.key";

options {

directory "/var/named/";

... ...

};

};

#Log Files

logging {

category queries {

default_syslog;

};

};

#DataBase Files

#注意view和match-clients的用法，就是它们在起作用

view "internal" {

match-clients { 10.0.0.0/8; };

recursion yes;

zone "." {

type hint;

file "named.ca";

};

zone "0.0.127.in-addr.arpa" {

type master;

file "0.0.127.in-addr.arpa.zone";

};

zone "localhost" {

type master;

file "localhost.zone";

};

zone "xxu.edu.cn" {

type master;

file "xxu.edu.cn.in.zone";

};

zone "10.in-addr.arpa" {

type master;

file "10.in-addr.arpa.zone";

};

};

view "external" {

match-clients { any; };

recursion yes;

zone "." {

type hint;

file "named.ca";

};

zone "0.0.127.in-addr.arpa" {

type master;

file "0.0.127.in-addr.arpa.zone";

};

zone "localhost" {

type master;

file "localhost.zone";

};

zone "xxu.edu.cn" {

type master;

file "xxu.edu.cn.out.zone";

};

zone "xx.xx.210.in-addr.arpa" {

type master;

file "xx.xx.210.in-addr.arpa.zone";

};

};

这样就配置好了！ 至于具体的数据文件，我想大家都应该会配置了，我这里就不多说了！