Re: [Asrg] DNSBL BCP v.2.0
Dear Nick & Co.,
Thank you for publishing this very nice DNSBL BCP draft! I personally,
still being a student, learned a lot of this paper and want to
share some of my thoughts.
> or flawed formmail scripts on web pages. Additional DNSBLs were > developed by others in order to address these changing tactics, and > today more than 700 DNSBLs are in operation.
I don't mistrust you, but I am very interested for the source of this
figure 700 :)
> When choosing to adopt a DNSBL, an administrator should keep the > following questions in mind: > 1. What is the intended use of the list? > 2. Does the list have a web site? > 3. Are the list's policies stated on the web site? > 4. Are the policies stated clearly and understandably? > 5. Are web pages for removal requirements accessible and > functioning properly? > 6. How long has the list been in operation? > 7. What are the demographics and quantity of the list's user base? > 8. Are comparative evaluations of the list available? > 9. What do your peers or members of the Internet community say > about the list.
Personally I would add the following:
- How much does the usage of the list cost?
- How can I access the list (DNS, rsync, HTTP, ..)?
> Most DNSBLs can effectively use a "no questions asked" removal > policy because by their very nature they will redetect or relist > problems almost immediately. They can mitigate more organized > attempts to "game" the system by elementary checking and rate- > limiting procedures, increasing lockout periods, rescans etc. > Furthermore, a few IP addresses more or less do not make a > significant difference in the overall effectiveness of a DNSBL. > Moreover, a "no questions asked" removal policy provides the > huge benefit of a swift reaction to incorrect listings.
What's when we talk about removing entire net ranges, e.g. a /8
network? IMHO its dangerous simply removing such an entry from
the list. On the other hand it should not only be possible to
remove single IP addresses, since some/most providers use MTAs
from at least /24 blocks to spread their mails.
> the DNSBL. There SHOULD NOT be any extra rules for de-listing > other than the ones listed in the published listing criteria.
Does this implicate removing SHOULD be cost-free?
> Removals SHOULD be possible in the absence of the list admin.
Why is this not a MUST? An absence will harm the list and of
course its users in a very bad way.
> 3.2. Cessation of List Operations MUST Be Done in a Graceful Fashion.
I suggest to add that list administrators SHOULD publish it (website,
newsletter, common mailing lists etc.) in time before going down.
Finally I feel the need for mentioning a news service in terms of
a newsletter or a mailing list. Some DNSxLs (e.g. ahbl.org) offer
such services that guarantee a user of this DNSxLs to be up-to-date.
I prefer this way of notification rather than polling on websites.
All the best,
/Christian
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Received on Tue Jun 19 08:30:44 2007
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