linux dns服务器配置

Linux上dns服务是一个域名解析的服务
实际安装为：
1. 查看服务器上是否安装了dns服务
# rpm -qa | grep bind
bind-utils-9.3.6-16.P1.el5
bind-9.3.6-16.P1.el5

# rpm -qa | grep name
caching-nameserver-9.3.6-16.P1.el5
需要有这几个rpm。
2. 修改配置文件（其实细心的人会发现次文件为链接文件，具体看下文错误2）
# cat /etc/named.caching-nameserver.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 { any; };
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";

// Those options should be used carefully because they disable port
// randomization
// query-source port 53;
// query-source-v6 port 53;

allow-query { any; };
allow-query-cache { any; };
};
logging {
channel default_debug {
file "data/named.run";
severity dynamic;
};
};
view localhost_resolver {
match-clients { any; };
match-destinations { any; };
recursion yes;
include "/etc/named.rfc1912.zones";
};

把以上的localhost和127.0.0.1都改成any，如果不改他只能让主机来访问。
3. 在/etc/named.rfc1912.zones文件中添加一些东西
# cat /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 "baidu.com" IN {
type master;
file "baidu.zheng";
};
红色部分为添加的，意图为正向解析
4. 上面添加的baidu.zheng文件应该在/var/named下面配置，进入目录执行命令cp named.zero baidu.zheng，其实这个目录下面应该是链接文件，真正的文件是放在/var/named/chroot/var/named下面，copy后baidu.zheng为正确的链接文件就对了，否则需要到/var/named/chroot/var/named目录下面创建，然后修改baidu.zheng文件
# cat /var/named/baidu.zheng
$TTL 86400
@ IN SOA localhost. root.localhost. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS dns.baidu.com.
dns IN A 10.10.247.119
www IN A 10.10.247.115
后面有注释，A即Address

localhost.localdomain为我的主机名，主机名可以在/etc/sysconfig/network下面修改，注销后生效
5. 重启dns使之生效，service named restart。
6. 测试：
# nslookup dns.baidu.com
;; Got recursion not available from 10.10.101.3, trying next server
Server: 10.10.101.8
Address: 10.10.101.8#53

Name: dns.baidu.com
Address: 202.108.22.220

# nslookup www.baidu.com
Server: 10.10.101.3
Address: 10.10.101.3#53

Non-authoritative answer:
www.baidu.com canonical name = www.a.shifen.com.
Name: www.a.shifen.com
Address: 61.135.169.105
Name: www.a.shifen.com
Address: 61.135.169.125
这里的错误原因是本机的dns没有更改还是用的局域网内的dns，更改dns再测试，下文的错误3，有具体解释。
修改后测试
# nslookup dns.baidu.com
Server: 10.10.247.119
Address: 10.10.247.119#53

Name: dns.baidu.com
Address: 10.10.247.119

# nslookup www.baidu.com
Server: 10.10.247.119
Address: 10.10.247.119#53

Name: www.baidu.com
Address: 10.10.247.115
7. 配置反向解析在/etc/named.rfc1912.zones文件下面添加以下行
zone "247.10.10.in-addr.arpa" IN {
type master;
file "baidu.fan";
};
我的ip是10.10.247网段的，所以黄色部分应该那样写，ip倒过来写
8. 拷贝文件cp /var/named/baidu.zheng /var/named/baidu.fan，如果拷贝后为链接文件就是对的，否则应该拷贝到/var/named/chroot/var/named，然后修改baidu.fan文件：
# cat baidu.fan
$TTL 86400
@ IN SOA localhost. root.localhost. (
1997022700 ; Serial
28800 ; Refresh
14400 ; Retry
3600000 ; Expire
86400 ) ; Minimum
IN NS baidu.com.
119 IN PTR dns.baidu.com.
115 IN PTR www.baidu.com.
红色部分为修改文件，前面的119 115为ip最后一位
9. 重启dns使之生效service named restart,然后执行命令nslookup 10.10.247.119，
# nslookup 10.10.247.119
Server: 10.10.247.119
Address: 10.10.247.119#53

119.247.10.10.in-addr.arpa name = dns.baidu.com.

# nslookup 10.10.247.115
Server: 10.10.247.119
Address: 10.10.247.119#53

115.247.10.10.in-addr.arpa name = www.baidu.com.

报错1.
# service named restart
停止 named：[确定]
启动 named：
named配置错误：:
zone localdomain/IN: loaded serial 42
zone localhost/IN: loaded serial 42
zone 0.0.127.in-addr.arpa/IN: loaded serial 1997022700
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: loaded serial 1997022700
zone 255.in-addr.arpa/IN: loaded serial 42
zone 0.in-addr.arpa/IN: loaded serial 42
dns_rdata_fromtext: baidu.zheng:9: near '10.10.247.119.': bad dotted quad
dns_rdata_fromtext: baidu.zheng:10: near '10.10.247.115.': bad dotted quad
zone baidu.com/IN: loading master file baidu.zheng: bad dotted quad
localhost_resolver/baidu.com/IN: bad dotted quad
[失败]
配置正向解析的时候有这个报错，后来反复测试发现在baidu.zheng文件中应该注意：

# cat baidu.zheng
$TTL 86400
@ IN SOA localhost. root.localhost. (
42 ; serial (d. adams)
3H ; refresh
15M ; retry
1W ; expiry
1D ) ; minimum
IN NS baidu.com.
dns IN A 10.10.247.119.
www IN A 10.10.247.115.
在ip后面的.应该去掉，做事情应该认真。
报错2.启动失败提示找不到文件**，一定要认准真正的目录在哪里，我这就犯了个这个问题，其实默认应该是在/var/named/下面创建向上文说的baidu.zheng、baidu.fan，但是细心的人会发现ll看一下
# ll
总计 52
drwxr-x--- 6 root named 4096 02-14 22:28 chroot
drwxrwx--- 2 named named 4096 2011-02-23 data
lrwxrwxrwx 1 root named 45 2011-11-20 localdomain.zone -> /var/named/chroot//var/named/localdomain.zone
lrwxrwxrwx 1 root named 43 2011-11-20 localhost.zone -> /var/named/chroot//var/named/localhost.zone
lrwxrwxrwx 1 root named 44 2011-11-20 named.broadcast -> /var/named/chroot//var/named/named.broadcast
lrwxrwxrwx 1 root named 37 2011-11-20 named.ca -> /var/named/chroot//var/named/named.ca
lrwxrwxrwx 1 root named 44 2011-11-20 named.ip6.local -> /var/named/chroot//var/named/named.ip6.local
lrwxrwxrwx 1 root named 40 2011-11-20 named.local -> /var/named/chroot//var/named/named.local
lrwxrwxrwx 1 root named 39 2011-11-20 named.zero -> /var/named/chroot//var/named/named.zero
drwxrwx--- 2 named named 4096 2011-02-23 slaves

文件都是链接文件，真正的文件在/var/named/chroot/var/named下面，在这个目录先买年创建文件，可以正常启动，不知道为什么都是链接文件，也许是我安装了rpm包然后卸载又重新安装的原因，或者他就是这样这样配置的，没有详细研究，根据个人配置而定。
报错3.解析不了，提示：
正向解析，反向解析都不行，随便举个例子：
# nslookup 10.10.247.119
;; Got recursion not available from 10.10.101.8, trying next server
Server: 10.10.101.3
Address: 10.10.101.3#53

** server can't find 119.247.10.10.in-addr.arpa.: NXDOMAIN

看一下本机的dns：
cat /etc/resolv.conf
; generated by /sbin/dhclient-script
search domain
nameserver 10.10.101.3
nameserver 10.10.101.8

我本地的dns服务器分别为10.10.101.3、10.10.101.8，所以他是跑去解析局域网内的dns服务器了，这是因为本机的dns默认是局域网内的，把dns修改成本地的即10.10.247.119即可。

报错4.
有时候解析不了，错误提示：
# nslookup www.baidu.com
;; connection timed out; no servers could be reached
这个的原因是文件所属问题，
# ll baidu.zheng
-rw-r----- 1 root root 477 02-14 23:48 baidu.zheng
把这里的百度所属改成named的chown :named baidu.zheng重启，问题解决