间歇访问网站

环境：

• 具有单个域控制器（Windows Server 2003 R2 Standard x64 Edition – Service Pack 2）的Active Directory域也是DNS

• Windows XP Service Pack 3客户端。 客户端计算机只有我们的内部DNS服务器作为他们的DNS地址。

我们的用户报告说偶尔他们不能访问西南航空网站www.southwest.com。

• 一般的OpenVPN + DNS策略
• Windows 2008 R2 – DNS +域名+电子邮件+网站
• 在DNS设置中，为什么要指定名​​称服务器和Alogging？
• 内联网网站; 有时使用计算机名称作品，othertimes知识产权作品…排他性和交替
• 使用自己的邮件服务器与外部域和DNS。 现在有内部的DNS。 dkimtesting不起作用

经过几天的尝试，我们能够在testing用户的login中重现问题。

当试图访问Firefox中的网站时，状态栏显示“查找www.southwest.com”，过了一会儿，Firefox显示：

地址未find

Firefox在www.southwest.com找不到服务器

类似的结果在Internet Explorer中

我们尝试重新启动浏览器和电脑，但我们仍然无法访问该网站。 我们testing的其他网站正常工作。

我们尝试从另一台计算机访问网站，并得到相同的结果。

nslookup揭示了以下内容：

C:\Documents and Settings\TestQ>nslookup www.teamdesk.net Server: server.domain.local Address: 172.21.31.206 Name: www.teamdesk.net Address: 208.100.33.78 C:\Documents and Settings\TestQ>nslookup www.southwest.com Server: server.domain.local Address: 172.21.31.206 DNS request timed out. timeout was 2 seconds. *** Request to server.domain.local timed-out C:\Documents and Settings\TestQ>nslookup Default Server: server.domain.local Address: 172.21.31.206 > www.southwest.com Server: server.domain.local Address: 172.21.31.206 DNS request timed out. timeout was 2 seconds. *** Request to server.domain.local timed-out > set d2 > www.southwest.com Server: server.domain.local Address: 172.21.31.206 ------------ SendRequest(), len 51 HEADER: opcode = QUERY, id = 4, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0 QUESTIONS: www.southwest.com.domain.local, type = A, class = IN ------------ ------------ Got answer (119 bytes): HEADER: opcode = QUERY, id = 4, rcode = NXDOMAIN header flags: response, auth. answer, want recursion, recursion avail. questions = 1, answers = 0, authority records = 1, additional = 0 QUESTIONS: www.southwest.com.domain.local, type = A, class = IN AUTHORITY RECORDS: -> domain.local type = SOA, class = IN, dlen = 41 ttl = 3600 (1 hour) primary name server = server.domain.local responsible mail addr = hostmaster serial = 2064 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) ------------ ------------ SendRequest(), len 35 HEADER: opcode = QUERY, id = 5, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0 QUESTIONS: www.southwest.com, type = A, class = IN ------------ DNS request timed out. timeout was 2 seconds. timeout (2 secs) SendRequest failed *** Request to server.domain.local timed-out > www.google.com Server: server.domain.local Address: 172.21.31.206 ------------ SendRequest(), len 48 HEADER: opcode = QUERY, id = 6, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0 QUESTIONS: www.google.com.domain.local, type = A, class = IN ------------ ------------ Got answer (116 bytes): HEADER: opcode = QUERY, id = 6, rcode = NXDOMAIN header flags: response, auth. answer, want recursion, recursion avail. questions = 1, answers = 0, authority records = 1, additional = 0 QUESTIONS: www.google.com.domain.local, type = A, class = IN AUTHORITY RECORDS: -> domain.local type = SOA, class = IN, dlen = 41 ttl = 3600 (1 hour) primary name server = server.domain.local responsible mail addr = hostmaster serial = 2064 refresh = 900 (15 mins) retry = 600 (10 mins) expire = 86400 (1 day) default TTL = 3600 (1 hour) ------------ ------------ SendRequest(), len 32 HEADER: opcode = QUERY, id = 7, rcode = NOERROR header flags: query, want recursion questions = 1, answers = 0, authority records = 0, additional = 0 QUESTIONS: www.google.com, type = A, class = IN ------------ ------------ Got answer (132 bytes): HEADER: opcode = QUERY, id = 7, rcode = NOERROR header flags: response, want recursion, recursion avail. questions = 1, answers = 6, authority records = 0, additional = 0 QUESTIONS: www.google.com, type = A, class = IN ANSWERS: -> www.google.com type = CNAME, class = IN, dlen = 8 canonical name = www.l.google.com ttl = 69859 (19 hours 24 mins 19 secs) -> www.l.google.com type = A, class = IN, dlen = 4 internet address = 74.125.239.19 ttl = 300 (5 mins) -> www.l.google.com type = A, class = IN, dlen = 4 internet address = 74.125.239.20 ttl = 300 (5 mins) -> www.l.google.com type = A, class = IN, dlen = 4 internet address = 74.125.239.18 ttl = 300 (5 mins) -> www.l.google.com type = A, class = IN, dlen = 4 internet address = 74.125.239.17 ttl = 300 (5 mins) -> www.l.google.com type = A, class = IN, dlen = 4 internet address = 74.125.239.16 ttl = 300 (5 mins) ------------ Non-authoritative answer: Name: www.l.google.com Addresses: 74.125.239.19, 74.125.239.20, 74.125.239.18, 74.125.239.17 74.125.239.16 Aliases: www.google.com 

我们如何进一步诊断和解决这个问题？

编辑

我和Brad一起工作。 感谢您一直以来的帮助。

1）DNS服务器充当parsing器。 除根服务器之外，没有通过根提示进行正向查找。

2）在错误状态（即，当southwest.com查找超时）时， nslookup southwest.com ns-1.southwest.com超时查找ns-1.southwest.com服务器。 与ns-2.southwest.com同样的事情。

3）在错误状态下， nslookup southwest.com 12.5.136.190和nslookup southwest.com 63.169.44.190 （即针对ns-1和ns-2.southwest.com的IP地址）均可正常工作，返回southwest.com的IP地址。

4）在错误状态下，当事情正常工作时，caching不变。 也就是说，dnsmgmt \ cached lookups。（root）\ com \ southwest总是显示以下内容（包括ns-2的Alogging，失败（参见上面的＃2））。

 Name Type Data ---- ---- ---- (same as parent folder) Name Server (NS) ns-1.southwest.com (same as parent folder) Name Server (NS) ns-2.southwest.com (same as parent folder) Host (A) 208.94.152.100 (same as parent folder) Host (A) 208.94.153.100 ns-2 Host (A) 63.169.44.190 

我怀疑我们忽略了一些明显的东西

编辑

（对不起，延迟，我发布了这个8小时以前，但它从来没有出现。）

在错误状态下，

5）nslookup southwest.com对所有* .gtld-servers.net服务器成功

 ... QUESTIONS: southwest.com, type = A, class = IN AUTHORITY RECORDS: -> southwest.com type = NS, class = IN, dlen = 7 nameserver = ns-1.southwest.com ttl = 172800 (2 days) -> southwest.com type = NS, class = IN, dlen = 7 nameserver = ns-2.southwest.com ttl = 172800 (2 days) ADDITIONAL RECORDS: -> ns-1.southwest.com type = A, class = IN, dlen = 4 internet address = 12.5.136.190 ttl = 172800 (2 days) -> ns-2.southwest.com type = A, class = IN, dlen = 4 internet address = 63.169.44.190 ttl = 172800 (2 days) ------------ Name: southwest.com Served by: - ns-1.southwest.com 12.5.136.190 southwest.com - ns-2.southwest.com 63.169.44.190 southwest.com 

6）nslookup southwest.com 208.67.222.222（OpenDNS）成功

7）清除caching解决了问题，但只是稍后返回。

8）在清除caching并执行nslookup southwest.com（成功）之后，caching现在具有ns-1的Alogging（它不在错误状态下，见上面的＃4）

 Name Type Data ---- ---- ---- (same as parent folder) Name Server (NS) ns-1.southwest.com (same as parent folder) Name Server (NS) ns-2.southwest.com (same as parent folder) Host (A) 208.94.153.100 (same as parent folder) Host (A) 208.94.152.100 ns-1 Host (A) 12.5.136.190 ns-2 Host (A) 63.169.44.190 

9）请注意，DNS服务器只转发到根服务器。 你能想到会导致这个问题的任何原因吗？