Repeated Blacklisting / IP reputation

Christopher Morrow morrowc.lists at
Wed Sep 16 02:40:53 UTC 2009

On Tue, Sep 15, 2009 at 10:29 PM,  <bmanning at> wrote:
> On Tue, Sep 15, 2009 at 09:34:14PM -0400, Christopher Morrow wrote:
>> On Tue, Sep 15, 2009 at 4:46 PM,  <bmanning at> wrote:
>> >
>> > so... this thread has a couple of really interesting characteristics.
>> > a couple are worth mentioning more directly (they have been alluded to elsewhere)...
>> as always, despite your choice in floral patterned shirts :) good
>> comments/questions.
>        humph... at least I wear pants.

you have something against skirts? or dresses? always with the pants
with you!! <shakey fist>

>> >
>> >        Who gets to define "bad" - other than a blacklist operator?
>> >        Are the common, consistent defintions of "contamination"?
>> nope, each BL (as near as I can tell) has their own criteria (with
>        trick question... each ISP gets to define good/bad on their
>        own merits or can outsource it to third parties.

sure... outsourcing in this case often happens without a real business

>> 1) newly allocated from IANA netblocks show up to end customers and
>> reachability problems ensue. (route-filters and/or firewall filters)
>> 2) newly re-allocated netblocks show up with RBL baggage (rbls and
>> smtp blocks at the application layer)
>        you forgot #3 ... a "clean" IANA block that was "borrowed"
>        for a while .. and already shows up in some filter lists.

ok... but we can't ever really know that Verizon uses 114/8 and 104/8
internally can we? (and has/may leak this to external parties on
occasion by mistake)

>> > So - I suspect that in the end, a registry (ARIN) or an ISP (COMCAST) is only
>> > going to be able to tell you a few things about the prefix you have been handed.
>> >
>> >        a) its virginal - never been used (that we know of)
>> >        b) its been used once.
>> >        c) it has a checkered past
>> I actually don't think it's a help for ARIN to say anything here,
>> since they can never know all the RBL's and history for a netblock,
>> and they can't help in the virginal case since they don't run
>> network-wide filters.
>        not RBL specific ...
>        a) this block came directly from IANA and has never been previously allocated
>           in/through the IANA/RIR process
>        b) this block has had one registered steward in recorded history
>        c) this block has been in/out of the RIR/registry system more than once.

Ok, is this in the final email from [email protected] to '[email protected]'? or
somewhere else? what's the recourse when someone says: "But I don't
want a USED netblock, it my have the herp!"

I'm trying to see if ARIN can say something of use here without
raising its costs or causing extra/more confusion to the end-site(s).

>> A FAQ that says some of the above with some pointers to testing
>> harnesses to use may be useful. Some tools for network operators to
>> use in updating things in a timely fashion may be useful.
>> Better/wider/louder notification 'services' for new block allocations
>> from IANA -> RIR's may be useful.
>        indeed - I'd like to see the suite extended to the ISPs as well, esp
>        if such tricks will be used in v6land...
>> last announced APNIC block yahtzee.  Where else is this data
>> available? In a form that your avg enterprise network op may notice?
>        oh... I'd suggest some of the security lists might be a good
>        channel.

sure, most of those folks also read nanog-l, this won't also reach
enterprise folk... (admittedly it's hard to reach 'everyone', but
spammers seem to be able to...)

>> > and it will be up to the receipient to trust/accept the resource for what it
>> > currently is or chose to reject it and find soliace elsewhere.
>> 'solace elsewhere'... dude there is no 'elsewhere'.
>        and yet... Jimmy and Warren Buffet will tell you its always 1700 somewhere....
>        and if that doesn't work,  whip out the NAT and reuse -again-.... :)

ha... :(


>> -Chris
>> (and yes, I'm yanking your chain about the shirts...)
>> > --bill
>> >
>> >
>> > On Tue, Sep 15, 2009 at 04:31:04PM -0400, Christopher Morrow wrote:
>> >> On Tue, Sep 15, 2009 at 4:23 PM,  <Valdis.Kletnieks at> wrote:
>> >> > On Tue, 15 Sep 2009 08:01:48 PDT, Shawn Somers said:
>> >> >
>> >> >>   Anyone that intentionally uses address space in a manner that they
>> >> >> know will cause it to become contaminated should be denied on any
>> >> >> further address space requests.
>> >> >
>> >> > You *do* realize that the people you're directing that paragraph at are
>> >> > able to say with a totally straight face: "We're doing nothing wrong and
>> >> > we have *no* idea why we end up in so many local block lists"?
>> >>
>> >> Also, you can very well disable new allocations to Spammer-Bob, did
>> >> you also know his friend Sue is asking now for space? Sue is very
>> >> nice, she even has cookies... oh damn after we allocated to her we
>> >> found out she's spamming :(
>> >>
>> >> Spammers have a lot of variables to change in this equation, RIR's
>> >> dont always have the ability to see all of the variables, nor
>> >> correlate all of the changes they see :(
>> >>
>> >> -Chris
>> >>
>> >

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