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Re: [Asrg] Please take a look at the blacklist BCP draft

2010-10-28 00:59:48
On 10/27/2010 6:12 AM, Hal Murray wrote:

Section 1.2, Guidance for DNSBL Users, is buried in the
Introduction.  That looks important enough to be a top level section.
Perhaps I'm expecting more than just Management (from the title).  How about
Management and Usage?

I'd been thinking about doing this a bit, but I've promised myself that if this BCP can actually go forward to something useful without too much (more) aggro, I'd write another more general BCP on spam filtering in general - that might be more palatable all the way up into the IETF than this BCP will likely be, and more prominently cover all these issues and more, and be far less aggro. That's probably a better place for promoting the subject, because it is far more general issue than just DNSBLs, and less political.

The "Guidance" section is more of an introduction of what DNSBL users should think about as an introduction to DNSBL policy/operational considerations than a series of IETF-ish SHOULDS/MUST NOTs etc.

Besides, after all this time, I don't have the lifespan for yet more major revisions ;-)

Section 2.2.2 A Direct Non-Public Way to Request Removal ... seems more like
an Operatonal detail (section 3) rather than a Policy issue.

No, that's definitely a policy item put there deliberately. SPEWS and APEWS style "go start a flame war in NANAE, you can't contact us no way no how, nyaa, nyaa" policy is what we were trying to discourage.

I've seen a lot of instances where listees simply won't do it, no matter how legitimate their claim is. Especially those who know about NANAE ;-)

IOW: a serious DNSBL should recognize that professionally handling queries via non-broadcast channels, and getting recognition for it (as some do), can only be of benefit to the list's accuracy, reputation and acceptance. Which can only improve the DNSBL user's experience.

Overall, much of it seems tailored to lists like the CBL that are highly
automated.  Would it be worth discussing lists with a lot of manual work?

I think the existing is sufficiently generalized to cover both highly automated and highly manual, with individual callouts where useful.

Things that might be worth discussing.  These aren't MUST/SHOULD type ideas,
but things that users and/or implementers might want to consider.

The following topics are far better handled in either the existing ASRG web page survey of techniques, or a more generalized spam filter FAQ.

   Whitelisting
     Maybe needed even with conservative lists.
     Easy whitelisting allows more aggressive filtering.
   Use URL or short-timeout Email address in rejection text.
     Needed to request whitelisting.
   Freemail providers
   Snowshoe spammers
   Low cost web farms
   Rogue ISPs
   Blocking whole countries
   Deep Receive header inspection
     Catches mail from Nigera via freemail or phish

Dynamic vs Generic confusion.

A company might want to block login from out-of-country IP Addresses to
reduce the damage from phished credentials.  This obviously needs a way to
bypass checking for people who do travel out of the country (if you have any)
and maybe only when they are traveling.

URL shorteners need aggressive anti-spam procedures or they will get listed.

Check DNSBLs before you rent IP-Addresses from an ISP, both their overall
reputation and the specific addresses you will get.

ARIN, RIPE, and such should park blocks that get returned long enough for
them to age out of block lists.  (or at least well run ones)  So should ISPs.

Perhaps ARIN and such should announce when blocks are returned and block
lists should watch for those announcements and automatically delist returned
blocks.  (Including private lists.)

Actually they do publish this information. You need to know it exists and how to use it.

I pull the CIDR/ASN allocation data for ARIN and the other RIRs from Potaroo to derive country codes on ASNs (but you can do it at the CIDR level too). You can tell when an allocation returns to ARIN, and when it goes back out again. Tho, I'm sure that Potaroo would be unhappy if everybody did it.

It might we worth reminding everybody that their abuse@ mailbox should work
and that whois info for CIDR blocks should include abuse contact info.  This
is both a way to avoid getting on block lists as well as a way for the block
list operator to contact you.

I don't want to make this BCP a squidlike mess of references to other documents. It can become obsolete far faster that way.

It needs to stay on focus at a higher level than these, which are really not DNSBL-specific.

Overall, I can't come up with a good suggestion for a top level organization.
  My straw man would be:
     Introduction
     Policy
     User side
     Server side
But it might need another section with more background between Intro and
Policy, for example more discussion of the breadth of reasons for listing and
how lists are used (envelope vs payload scanning)




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