> I couldn't say for sure what a safe level of queries would be. If I were > to guess, I'd say somewhere under 20,000 per 24 hour period.
Speaking for dnswl.org, we consider sites[*] with > 100k queries per 24 hour as "heavy users" who should rsync our data and run a local mirror. 20k will only show on the third or fourth page of the report which we hardly ever look at. A local mirror for net mass-checks may make sense for speed and reliability reasons; rsync access for dnswl.org is free. Since our data is rather small (at least when compared to a typical blocklist), it can also be handled as a BIND zone file (ie no rbldnsd is required, which makes handling local zones a bit easier). [*] We consider both individual querying IP addresses and the sum from queries from /24s. -- Matthias
