LINUX DNS服务器故障纠错 (分享来自:Mr.ZJunJun)

simonfirst

  DNS服务器故障纠错   .

2012-04-01 14:05 2798人阅读 评论(0) 收藏 举报

dns服务器loggingsocketsx86btservice


说明：这是一篇对DNS排错的文章，因为在网上（包括RedHat知识库）几乎没有对文中提到的错误进行直接描述和提出最好最快的解决方案的报告，经过长达近一个小时的排错和资料查阅才有了这篇文章的脱稿。

昨天我刚刚在非生产环境中的Red Hat Enterprise Linux Server上配置了一台DNS服务器，以做测试使用。但是很快遇到了一个奇怪的错误。

我在执行“service named status”后，其中第一行显示如下内容：

01.[root@localhost ~]# service named status
02.rndc: connect failed: 127.0.0.1#953: connection refused
03.named (pid  6207) is running...
04.[root@localhost ~]#  


一般大家都知道，rndc 主要是用来控制named进程及其配置文件的，可以用来连接DNS服务器并对配置进行重新载入，其端口号就是953。那么导致这个错误的原因可能是什么呢？

我的解决思路：

首先，发现问题，仔细阅读查看命令的回显信息。例如我详细的查看service的状态信息。
01.[root@localhost gdd]# service --status-all
02.abrtd (pid  2371) is running...
03.abrt-dump-oops (pid 2379) is running...
04.acpid (pid  2111) is running...
05.atd (pid  5396) is running...
06.auditd (pid  1833) is running...
07.automount (pid  2195) is running...
08.avahi-daemon (pid  2016) is running...
09.Usage: /etc/init.d/bluetooth {start|stop}
10.certmonger is stopped
11.Stopped
12.cgred is stopped
13.Frequency scaling enabled using ondemand governor
14.crond (pid  2423) is running...
15.cupsd (pid  2086) is running...
16.dnsmasq is stopped
17.dovecot is stopped
18.Usage: /etc/init.d/firstboot {start|stop}
19.hald (pid  2120) is running...
20.I don't know of any running hsqldb server.
21.httpd (pid  6595) is running...
22.Table: filter
23.Chain INPUT (policy ACCEPT)
24.num  target     prot opt source               destination         
25.1    ACCEPT     all      ::/0                 ::/0                state RELATED,ESTABLISHED  
26.2    ACCEPT     icmpv6    ::/0                 ::/0                 
27.3    ACCEPT     all      ::/0                 ::/0                 
28.4    ACCEPT     tcp      ::/0                 ::/0                state NEW tcp dpt:22  
29.5    REJECT     all      ::/0                 ::/0                reject-with icmp6-adm-prohibited  
30.
31.Chain FORWARD (policy ACCEPT)
32.num  target     prot opt source               destination         
33.1    REJECT     all      ::/0                 ::/0                reject-with icmp6-adm-prohibited  
34.
35.Chain OUTPUT (policy ACCEPT)
36.num  target     prot opt source               destination         
37.
38.IPsec stopped
39.Table: filter
40.Chain INPUT (policy ACCEPT)
41.num  target     prot opt source               destination         
42.1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED  
43.2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0            
44.3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            
45.4    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:953  
46.5    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:53  
47.6    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:443  
48.7    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22  
49.8    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited  
50.
51.Chain FORWARD (policy ACCEPT)
52.num  target     prot opt source               destination         
53.1    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited  
54.
55.Chain OUTPUT (policy ACCEPT)
56.num  target     prot opt source               destination         
57.
58.Table: mangle
59.Chain PREROUTING (policy ACCEPT)
60.num  target     prot opt source               destination         
61.
62.Chain INPUT (policy ACCEPT)
63.num  target     prot opt source               destination         
64.
65.Chain FORWARD (policy ACCEPT)
66.num  target     prot opt source               destination         
67.
68.Chain OUTPUT (policy ACCEPT)
69.num  target     prot opt source               destination         
70.
71.Chain POSTROUTING (policy ACCEPT)
72.num  target     prot opt source               destination         
73.
74.Table: nat
75.Chain PREROUTING (policy ACCEPT)
76.num  target     prot opt source               destination         
77.
78.Chain POSTROUTING (policy ACCEPT)
79.num  target     prot opt source               destination         
80.
81.Chain OUTPUT (policy ACCEPT)
82.num  target     prot opt source               destination         
83.
84.irqbalance (pid  1895) is running...
85.Kdump is operational
86.started
87.qpidd is stopped
88.matahari-qmf-hostd is stopped
89.matahari-qmf-networkd is stopped
90.matahari-qmf-serviced is stopped
91.matahari-qmf-sysconfigd is stopped
92.Checking for mcelog
93.mcelog is stopped
94.mdmonitor is stopped
95.messagebus (pid  1993) is running...
96.mysqld is stopped
97.rndc: connect failed: 127.0.0.1#953: connection refused
98.named is stopped
99.No open transaction
100.netconsole module not loaded
101.Configured devices:
102.lo eth0
103.Currently active devices:
104.lo eth0
105.NetworkManager (pid  2004) is running...
106.rpc.svcgssd is stopped
107.rpc.mountd is stopped
108.nfsd is stopped
109.rpc.rquotad is stopped
110.rpc.statd (pid  2037) is running...
111.nmbd is stopped
112.ntpd (pid  2243) is running...
113.oddjobd is stopped
114.portreserve (pid  1851) is running...
115.master (pid  2347) is running...
116.postmaster is stopped
117.Process accounting is disabled.
118.qpidd (pid  2390) is running...
119.quota_nld is stopped
120.rdisc is stopped
121.restorecond (pid 10836) is running...
122.rhnsd (pid  2445) is running...
123.rhsmcertd (pid 2457 2456) is running...
124.rngd is stopped
125.rpcbind (pid  1909) is running...
126.rpc.gssd is stopped
127.rpc.idmapd (pid 2076) is running...
128.rpc.svcgssd is stopped
129.rsyslogd (pid  185 is running...
130.sandbox is stopped
131.saslauthd is stopped
132.sfcb is not running, but pid file exists
133.smartd is stopped
134.smbd is stopped
135.snmpd is stopped
136.snmptrapd is stopped
137.spamd is stopped
138.spice-vdagentd is stopped
139.openssh-daemon (pid  2233) is running...
140.sssd is stopped
141.CIM server (2470) is runningtomcat6 is stopped             [  OK  ]
142.vsftpd is stopped
143.wdaemon is stopped
144.Webmin (pid 249 is running
145.wpa_supplicant (pid  2020) is running...
146.ypbind is stopped


很显然，上面的显示中的第97行显示的
rndc: connect failed: 127.0.0.1#953: connection refused
named is stopped



是错误的信息。

然后我开始查看系统日志，显示结果如下：
01.[root@localhost ~]# named -g
02.28-Mar-2012 13:27:58.722 starting BIND 9.7.3-P3-RedHat-9.7.3-8.P3.el6_2.2 -g
03.28-Mar-2012 13:27:58.722 built with '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' '--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--sharedstatedir=/var/lib' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--with-libtool' '--localstatedir=/var' '--enable-threads' '--enable-ipv6' '--with-pic' '--disable-static' '--disable-openssl-version-check' '--with-dlz-ldap=yes' '--with-dlz-postgres=yes' '--with-dlz-mysql=yes' '--with-dlz-filesystem=yes' '--with-gssapi=yes' '--disable-isc-spnego' '--with-docbook-xsl=/usr/share/sgml/docbook/xsl-stylesheets' 'build_alias=x86_64-redhat-linux-gnu' 'host_alias=x86_64-redhat-linux-gnu' 'target_alias=x86_64-redhat-linux-gnu' 'CFLAGS= -O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic' 'CPPFLAGS= -DDIG_SIGCHASE'
04.28-Mar-2012 13:27:58.722 adjusted limit on open files from 1024 to 1048576
05.28-Mar-2012 13:27:58.722 found 2 CPUs, using 2 worker threads
06.28-Mar-2012 13:27:58.723 using up to 4096 sockets
07.28-Mar-2012 13:27:58.734 loading configuration from '/etc/named.conf'
08.28-Mar-2012 13:27:58.735 reading built-in trusted keys from file '/etc/named.iscdlv.key'
09.28-Mar-2012 13:27:58.736 using default UDP/IPv4 port range: [1024, 65535]
10.28-Mar-2012 13:27:58.737 using default UDP/IPv6 port range: [1024, 65535]
11.28-Mar-2012 13:27:58.740 listening on IPv4 interface lo, 127.0.0.1#53
12.28-Mar-2012 13:27:58.744 binding TCP socket: address in use
13.28-Mar-2012 13:27:58.744 listening on IPv6 interface lo, ::1#53
14.28-Mar-2012 13:27:58.745 binding TCP socket: address in use
15.28-Mar-2012 13:27:58.747 could not open file '/var/run/named/named.pid': Permission denied
16.28-Mar-2012 13:27:58.747 generating session key for dynamic DNS
17.28-Mar-2012 13:27:58.747 could not open file '/var/run/named/session.key': Permission denied
18.28-Mar-2012 13:27:58.747 could not create /var/run/named/session.key
19.28-Mar-2012 13:27:58.747 failed to generate session key for dynamic DNS: permission denied
20.28-Mar-2012 13:27:58.753 using built-in trusted-keys for view _default
21.28-Mar-2012 13:27:58.754 set up managed keys zone for view _default, file 'dynamic/managed-keys.bind'
22.28-Mar-2012 13:27:58.754 automatic empty zone: 127.IN-ADDR.ARPA
23.28-Mar-2012 13:27:58.754 automatic empty zone: 254.169.IN-ADDR.ARPA
24.28-Mar-2012 13:27:58.754 automatic empty zone: 2.0.192.IN-ADDR.ARPA
25.28-Mar-2012 13:27:58.754 automatic empty zone: 100.51.198.IN-ADDR.ARPA
26.28-Mar-2012 13:27:58.754 automatic empty zone: 113.0.203.IN-ADDR.ARPA
27.28-Mar-2012 13:27:58.754 automatic empty zone: 255.255.255.255.IN-ADDR.ARPA
28.28-Mar-2012 13:27:58.754 automatic empty zone: 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.IP6.ARPA
29.28-Mar-2012 13:27:58.754 automatic empty zone: D.F.IP6.ARPA
30.28-Mar-2012 13:27:58.754 automatic empty zone: 8.E.F.IP6.ARPA
31.28-Mar-2012 13:27:58.754 automatic empty zone: 9.E.F.IP6.ARPA
32.28-Mar-2012 13:27:58.754 automatic empty zone: A.E.F.IP6.ARPA
33.28-Mar-2012 13:27:58.754 automatic empty zone: B.E.F.IP6.ARPA
34.28-Mar-2012 13:27:58.755 automatic empty zone: 8.B.D.0.1.0.0.2.IP6.ARPA
35.28-Mar-2012 13:27:58.759 none:0: open: /etc/rndc.key: file not found
36.28-Mar-2012 13:27:58.760 couldn't add command channel 127.0.0.1#953: file not found
37.28-Mar-2012 13:27:58.760 none:0: open: /etc/rndc.key: file not found
38.28-Mar-2012 13:27:58.760 couldn't add command channel ::1#953: file not found
39.28-Mar-2012 13:27:58.760 ignoring config file logging statement due to -g option
40.28-Mar-2012 13:27:58.761 zone 0.in-addr.arpa/IN: loaded serial 0
41.28-Mar-2012 13:27:58.762 zone 1.0.0.127.in-addr.arpa/IN: loaded serial 0
42.28-Mar-2012 13:27:58.764 zone 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.ip6.arpa/IN: loaded serial 0
43.28-Mar-2012 13:27:58.765 zone localhost.localdomain/IN: loaded serial 0
44.28-Mar-2012 13:27:58.766 zone localhost/IN: loaded serial 0
45.28-Mar-2012 13:27:58.766 managed-keys-zone ./IN: loading from master file dynamic/managed-keys.bind failed: permission denied
46.28-Mar-2012 13:27:58.766 dynamic/managed-keys.bind.jnl: open: permission denied
47.28-Mar-2012 13:27:58.766 managed-keys-zone ./IN: journal rollforward failed: unexpected error
48.28-Mar-2012 13:27:58.767 running


很明显，根据上面的结果第35，37，46行的提示很可能是权限或者配置文件的错误造成的。所以下面一一检查即可。

首先不是权限的问题。我查看了所有DNS相关的所有配置文件，展示如下，也为大家以后出错作为参考。因为使用root登录终端对文件或目录执行移动或创建工作很容易导致权限问题。
01.[root@localhost ~]# ls /var/named/ -al
02.total 40
03.drwxr-x---.  6 root  named 4096 Mar 28 13:05 .
04.drwxr-xr-x. 28 root  root  4096 Mar 28 13:44 ..
05.drwxr-x---.  6 root  named 4096 Mar 28 13:05 chroot
06.drwxrwx---.  2 named named 4096 Mar 28 13:23 data
07.drwxrwx---.  2 named named 4096 Mar 28 15:24 dynamic
08.-rw-r-----.  1 root  named 1892 Feb 18  2008 named.ca
09.-rw-r-----.  1 root  named  152 Dec 15  2009 named.empty
10.-rw-r-----.  1 root  named  152 Jun 21  2007 named.localhost
11.-rw-r-----.  1 root  named  168 Dec 15  2009 named.loopback
12.drwxrwx---.  2 named named 4096 Dec 20 23:53 slaves
13.[root@localhost ~]# ls /var/named/chroot/ -al
14.total 24
15.drwxr-x---. 6 root named 4096 Mar 28 13:05 .
16.drwxr-x---. 6 root named 4096 Mar 28 13:05 ..
17.drwxr-x---. 2 root named 4096 Mar 28 13:05 dev
18.drwxr-x---. 4 root named 4096 Mar 28 14:32 etc
19.drwxr-xr-x. 3 root root  4096 Mar 28 13:05 usr
20.drwxr-x---. 6 root named 4096 Mar 28 13:05 var
21.[root@localhost ~]# ls /var/named/chroot/etc/ -al
22.total 40
23.drwxr-x---. 4 root named 4096 Mar 28 14:32 .
24.drwxr-x---. 6 root named 4096 Mar 28 13:05 ..
25.-rw-r--r--. 1 root root   405 Oct 19 22:00 localtime
26.drwxr-x---. 2 root named 4096 Dec 20 23:53 named
27.-rw-r-----. 1 root named 1259 Mar 28 14:31 named.conf
28.-rw-r--r--. 1 root named 2544 Dec 20 23:53 named.iscdlv.key
29.-rw-r-----. 1 root named  931 Jun 21  2007 named.rfc1912.zones
30.-rw-r--r--. 1 root named  487 Dec 20 23:53 named.root.key
31.drwxr-xr-x. 3 root root  4096 Mar 28 13:05 pki
32.-rw-------. 1 root root   479 Mar 27 23:46 rndc.conf
33.[root@localhost ~]# ls /var/named/chroot/var -al
34.total 24
35.drwxr-x---. 6 root  named 4096 Mar 28 13:05 .
36.drwxr-x---. 6 root  named 4096 Mar 28 13:05 ..
37.drwxrwx---. 2 named named 4096 Dec 20 23:53 log
38.drwxr-x---. 6 root  named 4096 Mar 28 13:05 named
39.drwxr-x---. 3 root  named 4096 Mar 28 13:05 run
40.drwxrwx---. 2 named named 4096 Dec 20 23:53 tmp
41.[root@localhost ~]# ls /etc/named* -al
42.-rw-r-----. 1 root named 1259 Mar 28 14:31 /etc/named.conf
43.-rw-r-----. 1 root root   930 Mar 28 13:41 /etc/named.conf.backup
44.-rw-r--r--. 1 root named 2544 Dec 20 23:53 /etc/named.iscdlv.key
45.-rw-r-----. 1 root named  931 Jun 21  2007 /etc/named.rfc1912.zones
46.-rw-r--r--. 1 root named  487 Dec 20 23:53 /etc/named.root.key
47.
48./etc/named:
49.total 16
50.drwxr-x---.   2 root named  4096 Dec 20 23:53 .
51.drwxr-xr-x. 131 root root  12288 Mar 28 14:32 ..
52.[root@localhost ~]# ls /etc/rndc.* -al
53.-rw-------. 1 root root 479 Mar 27 23:46 /etc/rndc.conf
54.-rw-------. 1 root root 479 Mar 28 13:42 /etc/rndc.conf.backup
55.-rw-------. 1 root root 479 Mar 27 23:10 /etc/rndc.conf.original
56.-rw-------. 1 root root 479 Mar 27 23:46 /etc/rndc.conf.original_1_error_secret
57.-rw-------. 1 root root 510 Mar 27 23:43 /etc/rndc.key.removed_no_need
58.-rw-------. 1 root root 511 Mar 27 23:50 /etc/rndc.key.removed_no_need_1
59.[root@localhost ~]#  


通过比对之前的备份，发现在权限上没有问题。

PS:如果大家遇到这方面的问题请使用如下的命令进行修改。
01.su -
02.chown -R root:named /derectory/directory/file


那么既然不是权限的问题，是不是iptables给设定的规则不正确呢？

查看iptables配置信息，显示如下：
01.[root@localhost ~]# service iptables status
02.Table: nat
03.Chain PREROUTING (policy ACCEPT)
04.num  target     prot opt source               destination         
05.
06.Chain POSTROUTING (policy ACCEPT)
07.num  target     prot opt source               destination         
08.
09.Chain OUTPUT (policy ACCEPT)
10.num  target     prot opt source               destination         
11.
12.Table: mangle
13.Chain PREROUTING (policy ACCEPT)
14.num  target     prot opt source               destination         
15.
16.Chain INPUT (policy ACCEPT)
17.num  target     prot opt source               destination         
18.
19.Chain FORWARD (policy ACCEPT)
20.num  target     prot opt source               destination         
21.
22.Chain OUTPUT (policy ACCEPT)
23.num  target     prot opt source               destination         
24.
25.Chain POSTROUTING (policy ACCEPT)
26.num  target     prot opt source               destination         
27.
28.Table: filter
29.Chain INPUT (policy ACCEPT)
30.num  target     prot opt source               destination         
31.1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED  
32.2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0            
33.3    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0            
34.4    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:953  
35.5    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:53  
36.6    ACCEPT     tcp  --  10.0.0.0/8           0.0.0.0/0           tcp dpt:443  
37.7    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state NEW tcp dpt:22  
38.8    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited  
39.
40.Chain FORWARD (policy ACCEPT)
41.num  target     prot opt source               destination         
42.1    REJECT     all  --  0.0.0.0/0            0.0.0.0/0           reject-with icmp-host-prohibited  
43.
44.Chain OUTPUT (policy ACCEPT)
45.num  target     prot opt source               destination         
46.
47.[root@localhost ~]#  


显然，不是iptables的配置有问题。再者，iptables如果有策略在阻止访问，其错误信息也不是如上面所示。

最终我诊断为可能是/etc/named.conf 配置文件存在问题。

因此进行检查配置文件，操作和显示如下：
01.[root@localhost ~]# named-checkconf /etc/named.conf
02.[root@localhost ~]# named-checkconf -t /var/named/chroot/
03.[root@localhost ~]#  


说明，在参数上没有问题。因此我开始怀疑，是不是/etc/named.conf或者/etc/rndc.conf存在配置错误？但是，作为新配置安装的DNS不会在密钥上出现问题，因此我检查了/etc/named.conf，确实没发现什么错误。然后我检查了/etc/rndc.conf这个文件，终于发现问题的所在。

结果如下：


01.[root@localhost ~]# cat /etc/rndc.conf
02.# Start of rndc.conf
03.key "rndc-key" {
04.    algorithm hmac-md5;
05.    secret "cK1Bt77B8kL9uLpxy4GDTg==";
06.};
07.
08.options {
09.    default-key "rndc-key";
10.    default-server 127.0.0.1;
11.    default-port 953;
12.};
13.# End of rndc.conf
14.
15.# Use with the following in named.conf, adjusting the allow list as needed:
16.# key "rndc-key" {
17.#   algorithm hmac-md5;
18.#   secret "cK1Bt77B8kL9uLpxy4GDTg==";
19.# };
20.#  
21.# controls {
22.#   inet 127.0.0.1 port 953
23.#       allow { 127.0.0.1; } keys { "rndc-key"; };
24.# };
25.# End of named.conf


显然，最后的注释说的很清楚，要想使用rndc就必须在/etc/named.conf中进行配置。

所以将显示如下的/etc/named.conf第一段代码更改为第二段代码。

第一段代码：
01.[root@localhost ~]# cat /etc/named.conf
02.//
03.// named.conf
04.//
05.// Provided by Red Hat bind package to configure the ISC BIND named( DNS
06.// server as a caching only nameserver (as a localhost DNS resolver only).
07.//
08.// See /usr/share/doc/bind*/sample/ for example named configuration files.
09.//
10.
11.options {
12.    listen-on port 53 { 127.0.0.1; };
13.    listen-on-v6 port 53 { ::1; };
14.    directory   "/var/named";
15.    dump-file   "/var/named/data/cache_dump.db";
16.        statistics-file "/var/named/data/named_stats.txt";
17.        memstatistics-file "/var/named/data/named_mem_stats.txt";
18.    allow-query     { localhost; };
19.    recursion yes;
20.
21.    dnssec-enable yes;
22.    dnssec-validation yes;
23.    dnssec-lookaside auto;
24.
25.    /* Path to ISC DLV key */
26.    bindkeys-file "/etc/named.iscdlv.key";
27.};
28.
29.logging {
30.        channel default_debug {
31.                file "data/named.run";
32.                severity dynamic;
33.        };
34.};
35.
36.zone "." IN {
37.    type hint;
38.    file "named.ca";
39.};
40.
41.include "/etc/named.rfc1912.zones";


第二段代码：
01.[root@localhost ~]# cat /etc/named.conf
02.//
03.// named.conf
04.//
05.// Provided by Red Hat bind package to configure the ISC BIND named( DNS
06.// server as a caching only nameserver (as a localhost DNS resolver only).
07.//
08.// See /usr/share/doc/bind*/sample/ for example named configuration files.
09.//
10.
11.options {
12.    listen-on port 53 { 127.0.0.1; };
13.    listen-on-v6 port 53 { ::1; };
14.    directory   "/var/named";
15.    dump-file   "/var/named/data/cache_dump.db";
16.        statistics-file "/var/named/data/named_stats.txt";
17.        memstatistics-file "/var/named/data/named_mem_stats.txt";
18.    allow-query     { localhost; };
19.    recursion yes;
20.
21.    dnssec-enable yes;
22.    dnssec-validation yes;
23.    dnssec-lookaside auto;
24.
25.    /* Path to ISC DLV key */
26.    bindkeys-file "/etc/named.iscdlv.key";
27.};
28.
29.logging {
30.        channel default_debug {
31.                file "data/named.run";
32.                severity dynamic;
33.        };
34.};
35.
36.zone "." IN {
37.    type hint;
38.    file "named.ca";
39.};
40.
41.include "/etc/named.rfc1912.zones";
42.# Add line to enable named working with "/etc/rndc.conf"
43.
44.# Use with the following in named.conf, adjusting the allow list as needed:
45.key "rndc-key" {
46.       algorithm hmac-md5;
47.       secret "cK1Bt77B8kL9uLpxy4GDTg==";
48.};
49.
50.controls {
51.      inet 127.0.0.1 port 953
52.              allow { 127.0.0.1; } keys { "rndc-key"; };
53.};
54.# End of named.conf
55.
56.[root@localhost ~]#  


最后，重新启动named守护进程
01.su -
02.service named restart
03.service named status


结果显示如下，就表示可以了。
01.[root@localhost ~]# service named status
02.version: 9.7.3-P3-RedHat-9.7.3-8.P3.el6_2.2
03.CPUs found: 2
04.worker threads: 2
05.number of zones: 19
06.debug level: 0
07.xfers running: 0
08.xfers deferred: 0
09.soa queries in progress: 0
10.query logging is OFF
11.recursive clients: 0/0/1000
12.tcp clients: 0/100
13.server is up and running
14.named (pid  1191 is running...
15.[root@localhost ~]#  


最后总结：

        其实问题的出现不一定就是存在硬错误，还可能存在软错误。就像C编程一样，有的语法错误，编译器或语法检查器能帮你识别并找出错误，但是在算法上的逻辑错误只能由编程人员自己发现和纠正。在配置Linux网络服务器时同样也可能遇到这类问题，只要管理员仔细查看问题，检查日志就很快发现问题的所在。希望在今后的工作中能更多的总结和发现、解决问题的思路，大胆的却有根据的自己去发现和解决问题。