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沙发

楼主 |
发表于 2006-11-14 08:40:49
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只看该作者
经过了http://www.dnsstuff.com/tools/ptr.ch?ip=123.123.123.12
测试结果如下:
Location: China [City: Guangzhou, Guangdong]
Preparation:
The reverse DNS entry for an IP is found by reversing the IP, adding it to "in-addr.arpa", and looking up the PTR record.
So, the reverse DNS entry for 123.123.123.12 is found by looking up the PTR record for
12.123.123.123.in-addr.arpa.
All DNS requests start by asking the root servers, and they let us know what to do next.
See How Reverse DNS Lookups Work for more information.
How I am searching:
Asking a.root-servers.net for 12.123.123.123.in-addr.arpa PTR record:
a.root-servers.net says to go to ns1.apnic.net. (zone: 123.in-addr.arpa.)
Asking ns1.apnic.net. for 12.123.123.123.in-addr.arpa PTR record:
ns1.apnic.net [202.12.29.25] says to go to dns1.fz.fj.cn. (zone: 123.123.in-addr.arpa.)
Asking dns1.fz.fj.cn. for 12.123.123.123.in-addr.arpa PTR record: Reports that no PTR records exist [from 202.101.98.54].
Answer:
No PTR records exist for 123.123.123.12. [Neg TTL=86400 seconds]
Details:
dns1.fz.fj.cn. (an authoritative nameserver for 123.123.in-addr.arpa., which is in charge of the reverse DNS for 123.123.123.12)
says that there are no PTR records for 123.123.123.12.
To get reverse DNS set up for 123.123.123.12, you need to speak to your Internet provider. You could also
check with root@dns.fz.fj.cn., who is in charge of the 123.123.in-addr.arpa. zone.
Note that all Internet accessible hosts are expected to have a reverse DNS entry (per RFC1912 2.1),
and many mailservers (such as AOL) will likely block E-mail from mailservers with no reverse DNS entry.
To see the reverse DNS traversal, to make sure that all DNS servers are reporting the correct results, you can Click Here. |
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