nanog mailing list archives

RE: Spam. Again.. -- and blocking net blocks?


From: Mark Segal <MSegal () FUTUREWAY CA>
Date: Tue, 10 Dec 2002 15:33:33 -0500


I agree.. 

Problem was it was a downstream ISP.. This all comes down to, we warn them
since it is their customer, they don't deal with it, we black hole part of
their network.. 

But it take 3-4 days to do that to a large downstream.

Mark


--
Mark Segal
Director, Data Services
Futureway Communications Inc.
Tel: (905)326-1570


-----Original Message-----
From: Lee, Hansel [mailto:Hansel.Lee () corp winfirst com] 
Sent: December 10, 2002 3:08 PM
To: 'nanog () nanog org'
Cc: 'owner-nanog () merit edu'
Subject: RE: Spam. Again.. -- and blocking net blocks?



Quick Comment as a NANOG lurker and SPEWS lurker 
(news.admin.net-abuse.email).  I'm not defending SPEWS, don't 
speak for SPEWS but will describe what I understand happens: 

SPEWS initially lists offending IP address blocks from 
non-repentant SPAM sources.  If the upstream ISP does nothing 
about it, that block tends to expand to neighboring blocks to 
gain the attention of the ISP.

High level concept:
      Block the SPAMMER
              - ISP Does nothing
      Block the SPAMMER's Neighboring Blocks (Collateral Damage)
              - Motivates neighbors to find new Upstream/Isp
              - Motivates neighbors to complain to upstream/ISP
              - Gains the attention of the Upstream/ISP
      Expand the Block
              - Ditto
      Block the ISP as a whole

The SPEWS concept prevents an ISP from allowing spammers on 
some blocks while trying to service legitimate customers on 
others.  For an ISP - it is either all or none over time, you 
support spammers and are blocked as a whole (to include 
innocent customers). 

If you do end up mistakenly on SPEWS or take care of your 
spamming customers
- you can appeal to them at news.admin.net-abuse.email, get 
flamed pretty bad, and eventually fall off the list. 

I do personally like the idea of holding the ISP as a whole 
accountable over time.  An ISP can stay off spews, I've never 
had a block listed - though when I'm in a decision making 
position, I've never tolerated a spammer. 

Hansel


-----Original Message-----
From: Michael.Dillon () radianz com [mailto:Michael.Dillon () radianz com] 
Sent: Tuesday, December 10, 2002 08:36
To: MSegal () FUTUREWAY CA
Cc: nanog () nanog org; owner-nanog () merit edu
Subject: Re: Spam. Again.. -- and blocking net blocks?



Problem:
For some reason, spews has decided to now block one of our 
/19.. Ie no
mail
server in the /19 can send mail.

Questions:
1) How do we smack some sense into spews?

Make it easy for them to identify the fact that your downstream ISP 
customer has allocated that /32 to a separate organisation. 
This is what 
referral whois was supposed to do but it never happened because 
development of the tools fizzled out. 

If SPEWS could plug guilty IP addresses into an automated 
tool and come up 
with an accurate identification of which neighboring IP 
addresses were 
tainted and which were not, then they wouldn't use such crude 
techniques. 

Imagine a tool which queries the IANA root LDAP server for an 
IP address. 
The IANA server refers them to ARIN's LDAP server because 
this comes from 
a /8 that was allocated to ARIN. Now ARIN's server identifies 
that this 
address is in your /19 so it refers SPEWS to your own LDAP 
server. Your 
server identifies your customer ISP as the owner of the 
block, or if your 
customer has been keeping the records up to date with a simple LDAP 
client, your server would identify that the guilty party is 
indeed only on 
one IP address. 

Of course, this won't stop SPEWS from blacklisting you. But 
it enables 
SPEWS to quickly identify the organization (your customer 
ISP) that has a 
business relationship with the offender so that SPEWS is more 
likely to 
focus their attentions on these two parties.

2) Does anyone else see a HUGE problem with listing a /19 because 
there
is
one /32 of a spam advertised website?  When did this start 
happening?

It's a free country, you can't stop people like the SPEWS group from 
expressing their opinions. As long as people are satisfied with crude 
tools for mapping IP address to owner, this kind of thing 
will continue to 
happen.

--Michael Dillon



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