Steven_W提出的问题 -server

Steven_W

Asked: 2010-02-25 08:40:59 +0800 CST

两条 CNAME 记录的解析方式不同（Windows 2003 Server）

注意：这是在进一步调查后对早期问题的后续行动。

这个问题（到目前为止）似乎与 Win2003 DNS 服务器无关（尽管我没有尝试过其他服务器类型）

这些问题也（截至 2010 年 2 月 24 日）作为 MSDN 论坛帖子在这里公开，但我希望有人能够帮助测试其他服务器类型。

我遇到了一个相当奇怪的 DNS 问题（服务器 = Win2003）

我已经开始直接与我的 ISP 进行调查，我们遇到了一个奇怪的问题，如下所示。

注意：这些结果有时会以某种方式起作用（最好在清除 Win2003 DNS 缓存后立即执行测试）

首先，如果我们查看 wilmot.me.uk 的名称服务器记录，我们会得到：

>>> nslookup -q=cname mail.wilmot.me.uk
Non-authoritative answer:
   wilmot.me.uk    nameserver = primary-dns.co.uk
   wilmot.me.uk    nameserver = secondary-dns.co.uk

现在，有两条记录特别令人感兴趣。

>>> nslookup -q=cname mail.wilmot.me.uk
Non-authoritative answer:
   mail.wilmot.me.uk       canonical name = wilmot.me.uk.mail.aaisp.net.uk

>>> nslookup -q=cname mail2.wilmot.me.uk
Non-authoritative answer:
   mail2.wilmot.me.uk      canonical name = C.mail.aaisp.net.uk

现在问题似乎是本地 Windows 2003 DNS 服务器未正确遵循 CNAME 数据。

使用以下命令：

>>> nslookup -d2 -q=a mail.wilmot.me.uk.
>>> nslookup -d2 -q=a mail2.wilmot.me.uk.

我们可以看到：
mail.wilmot.me.uk 返回一个 NXDOMAIN 结果但是：
mail.wilmot.me.uk 返回一个带有 IP 地址的 NOERROR 结果（如预期的那样）。

似乎没有正确遵循 CNAME。

奇怪的是，以下两个都按预期返回。

>>> nslookup -q=a wilmot.me.uk.mail.aaisp.net.uk.
>>> nslookup -q=a C.mail.aaisp.net.uk.

如果有人可以帮助阐明这一点（即使通过确认“是的，它会导致 xxx OS 出现问题”或“似乎在 yyy OS 中工作正常”，那就太好了。

下面的日志数据显示 Win2003wilmot.me.uk.mail.aaisp.net.uk.在第一个实例中甚至没有尝试解析 CNAME

DNS Server log file creation at 24/02/2010 15:07:34 UTC

Message logging key (for packets - other items use a subset of these fields):
    Field #  Information         Values
    -------  -----------         ------
       1     Date
       2     Time
       3     Thread ID
       4     Context
       5     Internal packet identifier
       6     UDP/TCP indicator
       7     Send/Receive indicator
       8     Remote IP
       9     Xid (hex)
      10     Query/Response      R = Response
                                 blank = Query
      11     Opcode              Q = Standard Query
                                 N = Notify
                                 U = Update
                                 ? = Unknown
      12     [ Flags (hex)
      13     Flags (char codes)  A = Authoritative Answer
                                 T = Truncated Response
                                 D = Recursion Desired
                                 R = Recursion Available
      14     ResponseCode ]
      15     Question Type
      16     Question Name

20100224 15:07:36 D80 EVENT   The DNS server has started.

---

20100224 15:07:45 5A4 PACKET  00F421D0 UDP Rcv 10.0.0.102      0001   Q [0001   D   NOERROR] PTR   (1)2(1)0(1)0(2)10(7)in-addr(4)arpa(0)

20100224 15:07:45 5A4 PACKET  00F421D0 UDP Snd 10.0.0.102      0001 R Q [8085 A DR  NOERROR] PTR   (1)2(1)0(1)0(2)10(7)in-addr(4)arpa(0)

20100224 15:07:45 5A4 PACKET  00F42C80 UDP Rcv 10.0.0.102      0002   Q [0001   D   NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:45 5A4 PACKET  02349AE0 UDP Snd 192.36.148.17   a992   Q [0000       NOERROR] NS    (0)

20100224 15:07:45 5A4 PACKET  02344000 UDP Snd 128.63.2.53     b3cb   Q [0000       NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:45 5A4 PACKET  017E9FF0 UDP Rcv 192.36.148.17   a992 R Q [0084 A     NOERROR] NS    (0)

20100224 15:07:46 5A4 PACKET  017C7430 UDP Rcv 128.63.2.53     b3cb R Q [0080       NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:46 5A4 PACKET  02344000 UDP Snd 195.66.240.130  4caf   Q [0000       NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:46 5A4 PACKET  01706E30 UDP Rcv 195.66.240.130  4caf R Q [0080       NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:46 5A4 PACKET  02349AE0 UDP Snd 156.154.102.3   c5a7   Q [0000       NOERROR] A     (11)primary-dns(2)co(2)uk(0)

20100224 15:07:46 5A4 PACKET  01CF9870 UDP Rcv 156.154.102.3   c5a7 R Q [0080       NOERROR] A     (11)primary-dns(2)co(2)uk(0)

20100224 15:07:46 5A4 PACKET  02349AE0 UDP Snd 81.187.30.41    afb9   Q [0000       NOERROR] A     (11)primary-dns(2)co(2)uk(0)

20100224 15:07:46 5A4 PACKET  00F76370 UDP Rcv 81.187.30.41    afb9 R Q [0084 A     NOERROR] A     (11)primary-dns(2)co(2)uk(0)

20100224 15:07:46 5A4 PACKET  02344000 UDP Snd 81.187.30.41    bc45   Q [0000       NOERROR] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:46 5A4 PACKET  01C1C6D0 UDP Rcv 81.187.30.41    bc45 R Q [0384 A    NXDOMAIN] A     (4)mail(6)wilmot(2)me(2)uk(0)

20100224 15:07:46 5A4 PACKET  01C1C6D0 UDP Snd 10.0.0.102      0002 R Q [0384 A    NXDOMAIN] A     (4)mail(6)wilmot(2)me(2)uk(0)

---

20100224 15:07:49 5A4 PACKET  02343550 UDP Rcv 10.0.0.102      0001   Q [0001   D   NOERROR] PTR   (1)2(1)0(1)0(2)10(7)in-addr(4)arpa(0)

20100224 15:07:49 5A4 PACKET  02343550 UDP Snd 10.0.0.102      0001 R Q [8085 A DR  NOERROR] PTR   (1)2(1)0(1)0(2)10(7)in-addr(4)arpa(0)

20100224 15:07:49 5A4 PACKET  00F421D0 UDP Rcv 10.0.0.102      0002   Q [0001   D   NOERROR] A     (5)mail2(6)wilmot(2)me(2)uk(0)

20100224 15:07:49 5A4 PACKET  00F42C80 UDP Snd 81.187.30.41    42d0   Q [0000       NOERROR] A     (5)mail2(6)wilmot(2)me(2)uk(0)

20100224 15:07:49 5A4 PACKET  02311E70 UDP Rcv 81.187.30.41    42d0 R Q [0084 A     NOERROR] A     (5)mail2(6)wilmot(2)me(2)uk(0)

20100224 15:07:49 5A4 PACKET  00F42C80 UDP Snd 194.83.244.131  8601   Q [0000       NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  0179F2F0 UDP Rcv 81.187.81.33    8601 R Q [0080       NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  00F42C80 UDP Snd 195.66.240.130  8601   Q [0000       NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  0179FDA0 UDP Rcv 195.66.240.130  8601 R Q [0080       NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  02349AE0 UDP Snd 194.83.244.131  3e6d   Q [0000       NOERROR] A     (4)auth(13)secondary-dns(2)co(2)uk(0)

20100224 15:07:49 5A4 PACKET  01B36A50 UDP Rcv 81.187.81.32    3e6d R Q [0080       NOERROR] A     (4)auth(13)secondary-dns(2)co(2)uk(0)

20100224 15:07:49 5A4 PACKET  0234C590 UDP Snd 81.187.81.32    284a   Q [0000       NOERROR] A     (4)auth(11)primary-dns(2)co(2)uk(0)

20100224 15:07:49 5A4 PACKET  01E12130 UDP Rcv 81.187.81.32    284a R Q [0084 A     NOERROR] A     (4)auth(11)primary-dns(2)co(2)uk(0)

20100224 15:07:49 5A4 PACKET  00F42C80 UDP Snd 81.187.30.42    f980   Q [0000       NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  020E0CF0 UDP Rcv 81.187.30.42    f980 R Q [0084 A     NOERROR] A     (1)C(4)mail(5)aaisp(3)net(2)uk(0)

20100224 15:07:49 5A4 PACKET  00F421D0 UDP Snd 10.0.0.102      0002 R Q [8081   DR  NOERROR] A     (5)mail2(6)wilmot(2)me(2)uk(0)

20100224 15:07:57 D80 EVENT   The DNS server wrote version 567 of zone data-utilities.co.uk to file data-utilities.co.uk.dns.

---

Steven_W

Asked: 2010-02-19 18:25:32 +0800 CST

DNS 服务器 (MS) 返回 NXDOMAIN，原始返回 NOERROR

我的 ISP 最近对他们自己的 DNS 服务器配置进行了“小改动”。作为一个可能的巧合，这与我遇到本地 DNS 问题的时间差不多（谁知道呢，它可能是无关的，并且大约在同一时间链接到了 WinUpdate 补丁）

在查询我的本地 (Win2003) DNS 服务器和查询 ISP 的 DNS 服务器时，我似乎收到了不同的结果。

我无法弄清楚发生了什么变化（或配置错误）

1 - mail.wilmot.me.uk has a CNAME to wilmot.me.uk.mail.aaisp.net.uk  
    (as per [ISP Support page](http://aa.nu/kb-broadband-email.html/))
1b - wilmot.me.uk.mail.aaisp.net.uk resolves to 81.187.30.14, 81.187.30.19

2 - mail2.wilmot.me.uk (quick workaround added earlier)
    CNAME to mail.aaisp.net.uk
    Resolves to 81.187.30.14, 81.187.30.19

问题是：

针对本地服务器（10.0.0.2）...（一个Win2003盒子）

当我查找 mail.wilmot.me.uk 时，我得到一个 NXDOMAIN。
当我查找 mail2.wilmot.me.uk 时，我得到了预期的 IP 地址。

但是，如果我切换到 ISP 的解析器 (217.169.20.20)

当我查找 mail.wilmot.me.uk 时，我得到了预期的 IP 地址。
当我查找 mail2.wilmot.me.uk 时，我得到了预期的 IP 地址。

那么，为什么本地 DNS 服务器对 mail 和 mail2 的处理方式不同，而 ISP 的服务器却如预期一样响应

结果（在下面过滤）..在原始复制/粘贴错误后编辑

从 10.0.0.2

C:\>nslookup -debug mail.wilmot.me.uk. 10.0.0.2
-----------
Got answer:
    HEADER:
        opcode = QUERY, id = 2, rcode = NXDOMAIN
        header flags:  response, auth. answer
        questions = 1,  answers = 1,  authority records = 1,  additional = 0

    QUESTIONS:
        mail.wilmot.me.uk, type = A, class = IN
    ANSWERS:
    ->  mail.wilmot.me.uk
        canonical name = wilmot.me.uk.mail.aaisp.net.uk
        ttl = 3600 (1 hour)
    AUTHORITY RECORDS:
    ->  mail.aaisp.net.uk
        ttl = 600 (10 mins)
        primary name server = auth.primary-dns.co.uk
        responsible mail addr = a.k.gg
        serial  = 2010021105
        refresh = 10800 (3 hours)
        retry   = 3600 (1 hour)
        expire  = 1209600 (14 days)
        default TTL = 600 (10 mins)
------------
*** box2.data-utilities.co.uk can't find mail.wilmot.me.uk.: Non-existent domain

和：（mail2.wilmot.me.uk）

C:\>nslookup -debug mail2.wilmot.me.uk. 10.0.0.2
------------
Got answer:
    HEADER:
        opcode = QUERY, id = 2, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 3,  authority records = 0,  additional = 0

    QUESTIONS:
        mail2.wilmot.me.uk, type = A, class = IN
    ANSWERS:
    ->  mail2.wilmot.me.uk
        canonical name = c.mail.aaisp.net.uk
        ttl = 3600 (1 hour)
    ->  c.mail.aaisp.net.uk
        internet address = 81.187.30.14
        ttl = 656 (10 mins 56 secs)
    ->  c.mail.aaisp.net.uk
        internet address = 81.187.30.19
        ttl = 656 (10 mins 56 secs)
------------
Non-authoritative answer:
Name:    c.mail.aaisp.net.uk
Addresses:  81.187.30.14, 81.187.30.19
Aliases:  mail2.wilmot.me.uk

但是，当直接访问 ISP 的服务器时，结果显示正常

C:\>nslookup -debug mail.wilmot.me.uk. 217.169.20.20
Got answer:
    HEADER:
        opcode = QUERY, id = 2, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 3,  authority records = 1,  additional = 0

    QUESTIONS:
        mail.wilmot.me.uk, type = A, class = IN
    ANSWERS:
    ->  mail.wilmot.me.uk
        canonical name = wilmot.me.uk.mail.aaisp.net.uk
        ttl = 3600 (1 hour)
    ->  wilmot.me.uk.mail.aaisp.net.uk
        internet address = 81.187.30.14
        ttl = 3600 (1 hour)
    ->  wilmot.me.uk.mail.aaisp.net.uk
        internet address = 81.187.30.19
        ttl = 3600 (1 hour)
    AUTHORITY RECORDS:
    ->  mail.aaisp.net.uk
        ttl = 3600 (1 hour)
        primary name server = auth.primary-dns.co.uk
        responsible mail addr = support.aaisp.net.uk
        serial  = 1266576116
        refresh = 10800 (3 hours)
        retry   = 3600 (1 hour)
        expire  = 1209600 (14 days)
        default TTL = 600 (10 mins)
------------
Non-authoritative answer:
Name:    wilmot.me.uk.mail.aaisp.net.uk
Addresses:  81.187.30.14, 81.187.30.19
Aliases:  mail.wilmot.me.uk

和 mail2.wilmot.me.uk 也可以。

C:\>nslookup -debug mail2.wilmot.me.uk. 217.169.20.20
------------
Got answer:
    HEADER:
        opcode = QUERY, id = 2, rcode = NOERROR
        header flags:  response, want recursion, recursion avail.
        questions = 1,  answers = 3,  authority records = 2,  additional = 0

    QUESTIONS:
        mail2.wilmot.me.uk, type = A, class = IN
    ANSWERS:
    ->  mail2.wilmot.me.uk
        canonical name = C.mail.aaisp.net.uk
        ttl = 3600 (1 hour)
    ->  C.mail.aaisp.net.uk
        internet address = 81.187.30.19
        ttl = 614 (10 mins 14 secs)
    ->  C.mail.aaisp.net.uk
        internet address = 81.187.30.14
        ttl = 614 (10 mins 14 secs)
    AUTHORITY RECORDS:
    ->  mail.aaisp.net.uk
        nameserver = auth.primary-dns.co.uk
        ttl = 614 (10 mins 14 secs)
    ->  mail.aaisp.net.uk
        nameserver = auth.secondary-dns.co.uk
        ttl = 614 (10 mins 14 secs)
------------
Non-authoritative answer:
Name:    C.mail.aaisp.net.uk
Addresses:  81.187.30.19, 81.187.30.14
Aliases:  mail2.wilmot.me.uk

非常感谢对差异的任何见解。

我知道我可以坚持使用解决方法，但宁愿知道问题的原因，而不仅仅是如何“让它消失”

谢谢

两条 CNAME 记录的解析方式不同（Windows 2003 Server）

DNS 服务器 (MS) 返回 NXDOMAIN，原始返回 NOERROR

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Steven_W's questions

两条 CNAME 记录的解析方式不同（Windows 2003 Server）

DNS 服务器 (MS) 返回 NXDOMAIN，原始返回 NOERROR

新安装后 postgres 的默认超级用户用户名/密码是什么？

SFTP 使用什么端口？

命令行列出 Windows Active Directory 组中的用户？

什么是 Pem 文件，它与其他 OpenSSL 生成的密钥文件格式有何不同？

如何确定bash变量是否为空？