DNS故障解决小记

 

DNS故障解决小记

         配置了一台LINUX DNS服务器，完成所有配置文件后，开始进行测试,遇到一些小问题;
/etc/named.conf配置文件如下：
options {
        directory "/var/named";
        pid-file "/var/run/named/named.pid";
        forwarders {202.106.0.20;};
};
key "rndckey" {
        algorithm       hmac-md5;
        secret          "lFatFBZddzbn4IxnKOvZpDrVkBbqsWK4f8UIm3uGnPAJwRR1OsbHouMeDRAA";
};
 controls {
        inet 127.0.0.1 port 953
                allow { 127.0.0.1; } keys { "rndckey"; };
 };
 
zone "." {
        type hint;
        file "named.ca";
};
 
zone "localhost" {
        type master;
        file "named.local";
};
 
zone "0.0.127.in-addr.arpa" {
        type master;
        file "named.127.0.0";
};
 
zone "Kenson.com" {
        type master;
        file "kenson.com.zone"; //*正向解释
};
 
zone "0.0.10.in-addr.arpa" {
        type master;
        file "zone.kenson.com"; //*反向解释

};
各区域文件如下：
[root@server ~]# vi /var/named/kenson.com.zone
$TTL    86400
@        IN                     SOA  linux.kenson.com.       root.kenson.com. (
                                        42              ; serial (d. adams)
                                        3H              ; refresh
                                        15M             ; retry
                                        1W              ; expiry
                                        1D )            ; minimum
 
@               IN      NS      linux.kenson.com.
 
server          IN      A       192.168.1.50   //*记住A记录一定是指向IP地址
www           IN      A       192.168.1.50
winxp          IN      A       192.168.1.210

                 IN     MX 10   server          //*有邮件的必需有MX记录，优先级为10， 这里邮件服务器指向server ,切记，MX指向的服务器，必需加一条A记录即：server IN A 192.168.1.50.
 
 
 
[root@server ~]# vi /var/named/zone.kenson.com
@       IN      SOA     linux.kenson.com.   root.kenson.com.  (
                                                               1997022700 ; Serial
                                      28800      ; Refresh
                                      14400      ; Retry
                                      3600000    ; Expire
                                      86400 )    ; Minimum
@               IN      NS      linux.kenson.com.
 
50               IN      PTR     linux.kenson.com.
50               IN      PTR     www.kenson.com.
210              IN     PTR     winxp.kenson.com.
 
确何区域配置文件都没有错误，开始进行测试；
启动并观察端口情况；
[root@server ~]# service named start
[root@server ~]# netstat -ntulp | grep named
tcp        0      0 192.168.1.50:53             0.0.0.0:*                   LISTEN      13879/named
tcp        0      0 127.0.0.1:53                0.0.0.0:*                   LISTEN      13879/named
tcp        0      0 127.0.0.1:953               0.0.0.0:*                   LISTEN      13879/named
udp        0      0 0.0.0.0:32796               0.0.0.0:*                               13879/named
udp        0      0 192.168.1.50:53             0.0.0.0:*                               13879/named
udp        0      0 127.0.0.1:53                0.0.0.0:*                               13879/named
udp        0      0 :::32797                    :::*                                    13879/named
之前由于没有查看日志，直接开始下面的操作；强烈建议，安装完某服务后一定查看相关日志，确保服务能正常运行。
 [root@server ~]# nslookup
> www
Server:         192.168.1.50
Address:        192.168.1.50#53
** server can't find www: NXDOMAIN
> www.keywise.cn
Server:         192.168.1.50
Address:        192.168.1.50#53
** server can't find www.keywise.cn: SERVFAIL
 
查看日志得知是由于权限问题引起的；
Jul  7 23:26:49 server named[2788]: starting BIND 9.3.3rc2 -u named
Jul  7 23:26:49 server named[2788]: found 1 CPU, using 1 worker thread
Jul  7 23:26:49 server named[2788]: loading configuration from '/etc/named.conf'
Jul  7 23:26:49 server named[2788]: listening on IPv4 interface lo, 127.0.0.1#53
Jul  7 23:26:49 server named[2788]: listening on IPv4 interface eth0, 192.168.1.50#53
Jul  7 23:26:49 server named[2788]: command channel listening on 127.0.0.1#953
Jul  7 23:26:49 server named[2788]: command channel listening on ::1#953
Jul  7 23:26:49 server named[2788]: zone 0.0.10.in-addr.arpa/IN: loading master file named.10.0.0: permission denied
Jul  7 23:26:49 server named[2788]: zone 0.0.127.in-addr.arpa/IN: loaded serial 1997022700
Jul  7 23:26:49 server named[2788]: zone keywise.cn/IN: loading master file named.keywise.cn: permission denied
Jul  7 23:26:49 server named[2788]: zone localhost/IN: loaded serial 42
Jul  7 23:26:49 server named[2788]: running
 
查看配置文件的权限；
drwxr-x--- 5 root  named 4096 07-07 22:27 chroot
drwxrwx--- 2 named named 4096 2007-03-14 data
-rw-r----- 1 root  named  198 2007-03-14 localdomain.zone
-rw-r----- 1 root  root   521 07-07 23:24 zone.kenson.com
-rw-r----- 1 root  named  426 2007-03-14 named.127.0.0
-rw-r----- 1 root  named  427 2007-03-14 named.broadcast
-rw-r----- 1 root  named 2518 2007-03-14 named.ca
-rw-r----- 1 root  named  424 2007-03-14 named.ip6.local
-rw-r----- 1 root  root   293 07-07 23:09 kenson.com.zone
-rw-r----- 1 root  named  211 07-07 23:13 named.local
-rw-r----- 1 root  named  427 2007-03-14 named.zero
drwxrwx--- 2 named named 4096 2007-03-14 slaves
 
将以下这两区域文件的所属组为named，

#chgrp named kenson.com.zone

#chgrp named zone.kenson.ccom
rw-r----- 1 root  root   521 07-07 23:24 zone.kenson.com
-rw-r----- 1 root  root   293 07-07 23:09 kenson.com.zone

备注:做完上面的步骤,记住还有一个DNS文件要修改,是/etc/resolv.conf文件

seach kenson.com

nameserver 192.168.1.50  //*这条是手工增加的。

[root@server ~]# service named restart
停止 named：                                    [确定]
启动 named：                                    [确定]
[root@server ~]# nslookup
> server
Default server: 192.168.1.50
Address: 192.168.1.50#53
> www
Server:         192.168.1.50
Address:        192.168.1.50#53