nanog mailing list archives

Re: Repeated Blacklisting / IP reputation


From: Joe Greco <jgreco () ns sol net>
Date: Tue, 8 Sep 2009 14:16:31 -0500 (CDT)

On Tue, 8 Sep 2009, Joe Greco wrote:
It seems like it *could* be useful to have a system to notify of network
delegation changes, but it also seems like if this was particularly
important to anyone, then someone would have found a trivial way to
implement at least a poor man's version of it.  For example, record
the ASN of a blocked IP address and remove the block when the ASN
changes...

That too, would be easily gamed by spammers.  Just get multiple ASN's and 
bounce your dirty IPs around between them to clean them.  The IP space 
being a direct (RIR->LIR) allocation having been made after the blocking 
was initiated is a pretty clear sign that the space has actually changed 
hands, and seems like it would be fairly difficult (if at all possible) to 
game.

Right, but they'll only do that if they're aware of such a system and it
is significant enough to make a dent in them.  Further, it would be a
mistake to assume that *just* changing ASN's would be sufficient.  The
act of changing ASN's could act as a trigger to re-whois ARIN for an
update of ownership, for example.  The fact is that the information to
trigger a re-query of ownership upon a redelegation sort-of already
exists, though it is clearly imperfect.

My point was that if it was actually useful to "notice" when an IP
delegation moved, someone would already have made up a system to do this
somehow.

So my best guess is that there isn't a really strong incentive to pursue
some sort of notification system, because you could pretty much do it
as it stands.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.


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