On Mon, 14 Jul 2008, in the Usenet newsgroup comp.os.linux.networking, in
article <g5edrf$t2m$(E-Mail Removed)>, Fva... wrote:
>When I query this ip (210.209.58.7) reversely with nslookup command,
>I got this result
>"7.58.209.210-twnap."
>It seems to me that it is a abnormal DNS reply.
Yes, the admins at 'wonder.net.tw' which seems to be another name for
Nap Communications Inc in Taipei don't care how foolish they look.
>I can NOT ping it directly.
Not surprising - there is no 'twnap' domain at the top of the DNS tree.
>What happened?
Who ever set up the DNS (back in 2003 if the serial number follows the
normal convention) didn't bother to look at the results of their script,
and didn't test anything.
>Is this DNS query result correct ?
If you means does the PTR record point to a name with an A record, the
answer is obviously "no" but that isn't a specific requirement of RFCs
1032-1034 (but see RFC1035 Section 3.5 seventh paragraph).
Some would think this mismatch is a good reason to block traffic from
210.208.0.0 - 210.209.63.255. If it is important to you, contact the
owner of those blocks, or the Taiwan National Internet Registrar, or
APNIC citing RFC2050 Section 5. A whois query to APNIC should provide
the details you need.
Old guy
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