Linux多DNS服务

Linux多DNS服务

一、           实验目标

一台Linux服务器提供多个DNS服务。

二、           实验环境

Linux服务器版本为Red Hat Enterprise Linux Server release 5.2 (Tikanga)，内核版本号2.6.18-92.el5；两台客户端主机。

三、           实施步骤

1、  安装bind软件包

放入安装光盘，并切换到软件包所在目录，执行下列命令安装相应软件包：

rpm -ivh bind-9.3.4-6.P1.el5.i386.rpm

rpm -ivh bind-chroot-9.3.4-6.P1.el5.i386.rpm

rpm -ivh bind-devel-9.3.4-6.P1.el5.i386.rpm

rpm -ivh bind-libbind-devel-9.3.4-6.P1.el5.i386.rpm

rpm -ivh bind-libs-9.3.4-6.P1.el5.i386.rpm

rpm -ivh bind-sdb-9.3.4-6.P1.el5.i386.rpm

rpm -ihv bind-utils-9.3.4-6.P1.el5.i386.rpm

rpm -ivh caching-nameserver-9.3.4-6.P1.el5.i386.rpm

2、  创建、修改配置文件

1）  创建第二个DNS服务的相关配置文件

[root@server ~]#  cp -a /var/named /var/dns       注：-a参数保留目录及其以下文件属性

对链接文件重新链接到正确的目标文件。把/var/dns/chroot/var/named目录更名为/var/dns/chroot/var/dns

2）  第一个DNS服务修改后的内容如下：

[root@server ~]# cat /var/named/chroot/etc/named.conf

//

// named.caching-nameserver.conf

//

// Provided by Red Hat caching-nameserver 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.

//

// DO NOT EDIT THIS FILE - use system-config-bind or an editor

// to create named.conf - edits to this file will be lost on

// caching-nameserver package upgrade.

//

options {

        listen-on port 53 { 192.168.13.11; };

        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";

        query-source    port 53;

        query-source-v6 port 53;

};

logging {

        channel default_debug {

                file "data/named.run";

                severity dynamic;

        };

};

view localhost_resolver {

        recursion yes;

        include "/etc/named.rfc1912.zones";

};

[root@server ~]# cat /var/named/chroot/etc/named.rfc1912.zones

// named.rfc1912.zones:

//

// Provided by Red Hat caching-nameserver package

//

// ISC BIND named zone configuration for zones recommended by

// RFC 1912 section 4.1 : localhost TLDs and address zones

//

// See /usr/share/doc/bind*/sample/ for example named configuration files.

//

 

zone "." IN {

        type hint;

        file "named.ca";

};

 

zone "localdomain" IN {

        type master;

        file "localdomain.zone";

        allow-update { none; };

};

 

zone "localhost" IN {

        type master;

        file "localhost.zone";

        allow-update { none; };

};

 

zone "0.0.127.in-addr.arpa" IN {

        type master;

        file "named.local";

        allow-update { none; };

};

 

zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {

        type master;

        file "named.ip6.local";

        allow-update { none; };

};

 

zone "255.in-addr.arpa" IN {

        type master;

        file "named.broadcast";

        allow-update { none; };

};

 

zone "0.in-addr.arpa" IN {

        type master;

        file "named.zero";

        allow-update { none; };

};

 

zone "china.test" IN {

  type master;

  file "china.test.zone";

  allow-update { none; };

};

zone "13.168.192.in-addr.arpa" IN {

  type master;

  file "china.test.arpa";

  allow-update { none; };

};

3）  第二个DNS服务的主配置文件内容如下：

[root@server ~]# cat /var/dns/chroot/etc/dns.conf

//

// named.caching-nameserver.conf

//

// Provided by Red Hat caching-nameserver 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.

//

// DO NOT EDIT THIS FILE - use system-config-bind or an editor

// to create named.conf - edits to this file will be lost on

// caching-nameserver package upgrade.

//

options {

        listen-on port 54 { 192.168.13.11; };

        listen-on-v6 port 54 { ::1; };

        directory       "/var/dns";

        dump-file       "/var/dns/data/cache_dump.db";

        statistics-file "/var/dns/data/named_stats.txt";

        memstatistics-file "/var/dns/data/named_mem_stats.txt";

        query-source    port 54;

        query-source-v6 port 54;

};

logging {

        channel default_debug {

                file "data/named.run";

                severity dynamic;

        };

};

 

zone "." IN {

        type hint;

        file "named.ca";

};

 

zone "localdomain" IN {

        type master;

        file "localdomain.zone";

        allow-update { none; };

};

 

zone "localhost" IN {

        type master;

        file "localhost.zone";

        allow-update { none; };

};

 

zone "0.0.127.in-addr.arpa" IN {

        type master;

        file "named.local";

        allow-update { none; };

};

 

zone "0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa" IN {

        type master;

        file "named.ip6.local";

        allow-update { none; };

};

 

zone "255.in-addr.arpa" IN {

        type master;

        file "named.broadcast";

        allow-update { none; };

};

 

zone "0.in-addr.arpa" IN {

        type master;

        file "named.zero";

        allow-update { none; };

};

 

zone "china.test" IN {

  type master;

  file "china.test.zone";

  allow-update { none; };

};

zone "13.168.192.in-addr.arpa" IN {

  type master;

  file "china.test.arpa";

  allow-update { none; };

};

4）  第一个DNS服务的域文件内容如下：

[root@server ~]# cat /var/named/chroot/var/named/china.test.zone

$TTL    86400

@       IN      SOA     server.china.test.      admin.china.test. (

                        2009062100

                        28800

                        14400

                        360000

                        86400

                        )

                NS      server.china.test.

server          IN A    192.168.13.11

client          IN A    192.168.13.24

HT08126         IN A    192.168.13.23

[root@server ~]# cat /var/named/chroot/var/named/china.test.arpa

$TTL    86400

@               IN      SOA     server.china.test.      admin.china.test. (

                        2009062100

                        28800

                        14400

                        360000

                        86400

                        )

@       NS      server.china.test.

11      IN PTR  server.china.test.

23      IN PTR  HT08126.china.test.

24      IN PTR  client.china.test.

5）  第二个DNS服务的域名文件内容如下：

[root@server ~]# cat /var/dns/chroot/var/dns/china.test.zone          

$TTL    86400

@       IN      SOA     server.china.test.      admin.china.test. (

                        2009062100

                        28800

                        14400

                        360000

                        86400

                        )

                NS      server.china.test.

server          IN A    192.168.13.11

client          IN A    192.168.13.14

HT08126         IN A    192.168.13.13

[root@server ~]# cat /var/dns/chroot/var/dns/china.test.arpa

$TTL    86400

@               IN      SOA     server.china.test.      admin.china.test. (

                        2009062100

                        28800

                        14400

                        360000

                        86400

                        )

@       NS      server.china.test.

11      IN PTR  server.china.test.

13      IN PTR  HT08126.china.test.

14      IN PTR  client.china.test.

 

3、  开启DNS服务

/usr/sbin/named -u named -c /etc/named.conf -t /var/named/chroot/

/usr/sbin/named -u named -c /etc/dns.conf -t /var/dns/chroot/

4、  配置防火墙，使不同的客户端得到不同的解析结果。

iptables -t nat -A PREDNS -p udp --dport 53 -s 192.168.13.24 -j REDIRECT --to 54

iptables -t nat -A PREDNS -p tcp --dport 53 -s 192.168.13.24 -j REDIRECT --to 54

5、  制作启动脚本，内容如下：

[root@server init.d]# cat dns

#!/bin/bash

 

NAMED_CONF="/etc/named.conf"

NAMED_CHROOT="/var/named/chroot/"

DNS_CONF="/etc/dns.conf"

DNS_CHROOT="/var/dns/chroot/"

 

start()

{

  echo -n $"Starting named:  "

  if [ -r ${NAMED_CHROOT}${NAMED_CONF} ]; then

    /usr/sbin/named -u named -c ${NAMED_CONF} -t ${NAMED_CHROOT}

    if [ "`ps aux | grep "$NAMED_CONF" | grep -v "grep" | awk '{print $2}'`" = "`cat ${NAMED_CHROOT}/var/run/named/named.pid`" ]

    then

      echo -e "          [ \033[;32m OK  \033[;37m ]"

    else

      echo -e "          [ \033[;31mFiled\033[;37m ]"

    fi

  else

    echo "${NAMED_CHROOT}${NAMED_CONF} cound not open! please check...."

  fi

  echo -n $"Starting dns:    "

  if [ -r ${DNS_CHROOT}${DNS_CONF} ]; then

    /usr/sbin/named -u named -c ${DNS_CONF} -t ${DNS_CHROOT}

    if [ "`ps aux | grep "$DNS_CONF" | grep -v "grep" | awk '{print $2}'`" = "`cat ${DNS_CHROOT}/var/run/named/named.pid`" ]

    then

      iptables -t nat -N PREDNS

      iptables -t nat -F PREDNS

      iptables -t nat -A PREDNS -p udp --dport 53 -s 192.168.13.24 -j REDIRECT --to 54

      iptables -t nat -A PREDNS -p tcp --dport 53 -s 192.168.13.24 -j REDIRECT --to 54

      until [ -z "`iptables -t nat -L PREROUTING -vn | grep PREDNS`" ]

      do

        iptables -t nat -D PREROUTING -j PREDNS

      done

      iptables -t nat -I PREROUTING -j PREDNS

      echo -e "          [ \033[;32m OK  \033[;37m ]"

    else

      echo -e "          [ \033[;31mFiled\033[;37m ]"

    fi

  else

    echo "${DNS_CHROOT}${DNS_CONF} cound cont open! please check...."

  fi

}

 

stop()

{

  if [ -z "`ps aux | grep "$NAMED_CONF" | grep -v "grep" | awk '{print $2}'`" ]

  then

    echo -e "Stopping named:            [ \033[;31mFiled\033[;37m ]"

  else

    kill -9 `ps aux | grep "$NAMED_CONF" | grep -v "grep" | awk '{print $2}'`

    echo -e "Stopping named:            [ \033[;32m OK  \033[;37m ]"

  fi

  if [ -z "`ps aux | grep "$DNS_CONF" | grep -v "grep" | awk '{print $2}'`" ]

  then

    echo -e "Stopping dns:              [ \033[;31mFiled\033[;37m ]"

  else

    until [ -z "`iptables -t nat -L PREROUTING -vn | grep PREDNS`" ]

    do

      iptables -t nat -D PREROUTING -j PREDNS

    done

    iptables -t nat -F PREDNS

    iptables -t nat -X PREDNS

    kill -9 `ps aux | grep "$DNS_CONF" | grep -v "grep" | awk '{print $2}'`

    echo -e "Stopping dns:              [ \033[;32m OK  \033[;37m ]"

  fi 

}

 

restart()

{

        stop

        sleep 2

        start

}

 

status()

{

  if [ -z "`ps aux | grep "$NAMED_CONF" | grep -v "grep" | awk '{print $2}'`" ]

  then

    echo -e "\033[;31m named stopping... \033[;37m"

  else

    echo -e "\033[;32m named running... \033[;37m"

  fi

  if [ -z "`ps aux | grep "$DNS_CONF" | grep -v "grep" | awk '{print $2}'`" ]

  then

    echo -e "\033[;31m dns stopping... \033[;37m"

  else

    echo -e "\033[;32m dns running... \033[;37m"

  fi

}

 

case "$1" in

        start)

                start

                ;;

        stop)

                stop

                ;;

        restart)

                restart

                ;;

        status)

                status

                ;;

        *)

                echo $"Usage: $0 {start|stop|status|restart}"

                exit 2

esac

6、  设置脚本可执行，并添加到/usr/sbin目录

[root@server ~]# chmod +x /etc/init.d/dns

[root@server ~]# cp /etc/init.d/dns /usr/sbin/dns

7、  设置自启动

[root@server ~]# echo "/usr/sbin/dns start" >> /etc/rc.d/rc.local

四、           测试与结论

主机A的测试结果如下：

C:\>ipconfig/all

 

Ethernet adapter lonet1:

 

        Connection-specific DNS Suffix  . :

        Description . . . . . . . . . . . : Microsoft Loopback Adapter #2

        Physical Address. . . . . . . . . : 02-00-4C-4F-4F-50

        Dhcp Enabled. . . . . . . . . . . : No

        IP Address. . . . . . . . . . . . : 192.168.13.12

        Subnet Mask . . . . . . . . . . . : 255.255.255.0

        Default Gateway . . . . . . . . . :

        DNS Servers . . . . . . . . . . . : 192.168.13.11

 

C:\>nslookup client.china.test

Server:  server.china.test

Address:  192.168.13.11

 

Name:    client.china.test

Address:  192.168.13.24

 

 

主机B的测试结果如下：

[root@client ~]# ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0C:29:71:C6:09 

          inet addr:192.168.13.24  Bcast:192.168.13.255  Mask:255.255.255.0

          inet6 addr: fe80::20c:29ff:fe71:c609/64 Scope:Link

          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

          RX packets:2674 errors:0 dropped:0 overruns:0 frame:0

          TX packets:779 errors:0 dropped:0 overruns:0 carrier:0

          collisions:0 txqueuelen:1000

          RX bytes:219817 (214.6 KiB)  TX bytes:105427 (102.9 KiB)

          Interrupt:169 Base address:0x2000

 

[root@client ~]# cat /etc/resolv.conf

; generated by /sbin/dhclient-script

search china.test

nameserver 192.168.13.11

 

[root@client init.d]# ping client.china.test

PING client.china.test (192.168.13.14) 56(84) bytes of data.

 

结论：实现了实验目标。