We did swip the block to the isp (as an assignment, not allocation).. That is the problem, they kept recursively looking up the assignment.. Maybe they should block 64/8 or maybe 0/0 :). Anybody interested in a coordinated denial of service attack? :). Mark -- Mark Segal Director, Data Services Futureway Communications Inc. Tel: (905)326-1570

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

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

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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.

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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