Vanja Hrustic wrote:
> 
> Small & silly problem.
>
> Intranet ==> DNS ==> Intenet
>
> In this case, DNS is the machine that has assigned 'normal' IP address
> (visible/accessible from Internet), and is used to resolve Internet
> addresses for Intranet users.

Humm, does this host also have an NS record entry with the InterNIC or
within your SOA? I ask because you say "is used to resolve Internet
addresses". It is not clear if this means:
1) Only internal hosts use it for name resolution
2) Everyone (Internet) uses it for DNS resolution

> The question.
>
> Is there any reason why DNS server should accept connections at port 53
> (tcp or/and udp) from the 'outer' world? As much as I can understand, there
> is no need. But... I ask, just to make sure :)

If you are running under option #1 above *and* the system has no
InterNIC or SOA NS record, then no you should not need to accept
connections to this machine.

What you are probably seeing are the obnoxious reverse connections a
number of sites like DoubleClick are using these days in order to zone
in on your physical location. You may also see connection attempts to
the TCP-Echo port of your name server.

Speaking of which, has anyone noticed what Altavista has been up to
these days? If you have a DoubleClick cookie entry, try the following:
1) Go to http://www.altavista.com
2) Enter a search string
3) Sniff the outbound connection

What you will see is the local system creating a connection to
http://ad.doubleclick.net/adi/altivista.digital.com/ in order to send
the following string:
result_front;kw=all+search+words+you+entered;ord=nine_digit_ID_number

I still need to get my ducks lined up on this one, but I believe the
"odr" number is your DoubleClick ID/Cookie number. If this is true, then
Altavista is reporting to DoubleClick any searches you perform on their
site. Scary stuff. I have not seen this with any other major search
engine.

I'm also curious if anyone has seen this type of activity when they
place an on-line order. The possibilities get really scary if you add
personal information to the data that DoubleClick is already collecting.
And to think we where worried about the government becoming "Big
Brother". ;)

Just wondering if anyone else has played around with this stuff and can
confirm or deny.

Cheers,
Chris
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