nanog mailing list archives

Re: Open Resolver Problems


From: Jared Mauch <jared () puck nether net>
Date: Mon, 25 Mar 2013 11:55:12 -0400


On Mar 25, 2013, at 11:44 AM, Valdis.Kletnieks () vt edu wrote:

On Mon, 25 Mar 2013 15:38:01 -0000, Nick Hilliard said:
On 25/03/2013 14:33, Mikael Abrahamsson wrote:
I would like to be able to request an IP list of open resolvers in my ASN,
perhaps sent to the contact details in RIPE whois database to make sure I'm
not falsely representing that ASN.

Why would that matter?  This is publicly available information.

Some of us have both publicly-facing authoritative DNS, and inward
facing recursive servers that may be open resolvers but can't be
found via NS entries (so the IP addresses of those aren't exactly
publicly available info).

Scoping your responses based on query-source should work just fine in this case.

There's documentation on how to do that online here:

http://www.zytrax.com/books/dns/ch9/close.html

I highly recommend doing this with your name server.  If you have examples of how to do this you want to share and have 
me post, as I mentioned, please send me your edits and additions.  I want to make this valuable.

- Jared

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