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Re: what the heck do i do now?

  • From: John Payne
  • Date: Tue Feb 06 01:37:53 2007
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On Feb 6, 2007, at 12:40 AM, Jeremy Chadwick wrote:

On Mon, Feb 05, 2007 at 10:13:08PM -0500, Jon Lewis wrote:
On Mon, 5 Feb 2007, Jeremy Chadwick wrote:
1) DNS servers which are not configured to blackhole IANA-reserved
 network blocks (read: the majority) will blindly try to reach and friends. - This block is assigned as "TEST-NET" for use in
documentation and example code. It is often used in conjunction with
domain names or in vendor and protocol
documentation. Addresses within this block should not appear on the
public Internet.

I was going purely off of what ARIN reports:

Internet Assigned Numbers Authority RESERVED-192 (NET-192-0-0-0-1)
Internet Assigned Numbers Authority IANA (NET-192-0-2-0-1)

If there is something magical about, then I'd love to
know what it is (please do educate me!).  But from my perspective, it
just looks like another IANA-reserved netblock.

RFC 3330 - This block is assigned as "TEST-NET" for use in
documentation and example code. It is often used in conjunction with
domain names or in vendor and protocol
documentation. Addresses within this block should not appear on the
public Internet.

BTW - there's nothing that says anything about filtering It might be reserved for IANA, but there's nothing saying it can't be used. Looks to me like ICANN is using some of their sub-allocation in that space.

That /24 doesn't show up in BGP unless something is broken or you have a
cymru bogon feed. Either way, worst case is you're default routing to an
ISP/NSP and the packets get a few hops before someone drops them as

Right, so the mentality here is that "someone" will eventually filter the packets or they'll be dropped due to a null route BGP rule. This I understand, but IMHO it's better to filter such packets before they ever reach someone else's networking gear. (Sorry if I'm not phrasing this as eloquently as possible.) In my case, I simply purchase co-lo space from providers and rely on their routing configurations, hoping they're doing things properly. But as one can see from the ipfw stats I pasted, some aren't. Understand where I'm coming from?

Packets destined for will follow the money trail. As soon as someone stops paying, the packets will die. (Actually sometimes they'll drop off sooner than the money trail, but that's irrelevant). What I'm saying is that by sending packets to the only people who'll be "harmed" by that action are people you're paying.

2) Some people (like myself) have ipfw/pf rules which block and
 log outbound packets to reserved blocks.  We log these because
 usually it's the sign of broken software or possibly some weird
 IP routing (read: OS IP stack) problem.  In the case of ipfw (I
 haven't tested pf), the block gets reported to underlying layers
 as EACCES, which can be incredibly confusing for admins.

If it means they get noticed, mission accomplished. That's exactly what
Paul wants.

In that case, it's a win-win situation.

Which is probably why it was suggested....

My vote is to simply remove the NS and A records for
and let people utilise search engines and mailing list archives to
figure out where to go (mail-abuse).

The NS's will get slammed with all the DNSBL queries then.
The suggestions I made at least get some of the queriers (assuming they
have properly functioning caches) off your back for a while.

Hmm, yes, you're absolutely correct. But I'm curious why you picked rather than some other reserved block? (I've also sent a copy of this discussion to an associate of mine at Nominum, who's now wondering the same thing I am...)

Pointing to RFC 1918 space is likely to cause "harm". is guaranteed not to (unless people don't follow RFC allocations....)

I've found this thread immensely educational so far!

| Jeremy Chadwick jdc at |
| Parodius Networking http:// |
| UNIX Systems Administrator Mountain View, CA, USA |
| Making life hard for others since 1977. PGP: 4BD6C0CB |