November 1st is the “birthday” of dnswl.org. Two years ago, in 2006, the project went public with a modestly sized amount of data and amateurish DNS server setup (a single machine off my private DSL line).
We are now running an infrastructure of 14 nameservers (most of which donated by various third parties — a warm thank you!), and over 42’000 database entries (covering 1.9 Mio IP addresses), maintained by six active administrators through roughly 4’500 edits per month. Additonally, we import data from other sources, like eg the provider associations of Spain, Austria, and Switzerland.
It is hard to tell how many “users” dnswl.org has, but we can approximate:
- On the three DNS servers where we have very detailled statistics, we see queries from roughly 55’000 networks (IP addresses aggregated into /24s). There is some overlap in this data, but if we extrapolate carefully, there are about 100’000 to 200’000 networks querying dnswl.org data over DNS.
- There are over 350 unique /24 networks getting dnswl.org data over rsync. This includes organisations like eg universities, companies, and government agencies, but also strong multipliers like email outsourcing providers, and the occasional hobbyist / private server of a geek. It’s hard to guess the number of actual users with any specifity, but given that some big email outsourcing providers are getting the data over rsync, it would be fair to guess that the reach over rsync is roughly equal to that over DNS.
- The third category of users is indirect — some DNSBL operators use dnswl.org data to finetune their listing criteria (a server listed in dnswl.org may have higher thresholds before being blacklisted, eg). This “second order effect” of dnswl.org affects a far bigger number of users than the two categories above.
In sum, it seems fair to assume that dnswl.org data affects a majority of email users around the world. The dnswl.org project is very well aware of the responsibility associated with this reach, and works diligently to improve the quality of it’s data.
Contributions to dnswl.org are always welcome — please drop as an email: admins (at) dnswl.org (or use the request form at http://www.dnswl.org/request.pl for listings)
