>>>>> "Peter" == Peter Bowyer <[EMAIL PROTECTED]> writes:
Peter> Do you have enough DNS bandwidth for this? Bear in mind that Peter> queries for the subdomain will hit the main domain servers Peter> first, so you'll get double traffic for each subdomain query, It's not double, because the NS records for the subdomain do get cached and subsequent queries go directly to the subdomain's NSes. However, it _can_ in practice reach 10% of the query traffic (or more if you are really unlucky), an insanely high figure primarily caused by two specific broken versions of BIND (8.3.3 and 8.3.4 iirc). Also, DNSBLs are (more than regular DNS servers are) often queried by software which is written by poorly-trained chimps who think they can re-implement their own recursive resolver without caching, which adds to the parent-zone query load (though not nearly as much as the BIND breakage does). In addition, the parent zone has to handle the query load caused by everyone who typos or misconfigures the DNSBL name (the number of DNS queries for "n.n.n.n.http://sbl-xbl.spamhaus.org"; alone is truly terrifying). -- Andrew, Supernews http://www.supernews.com -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
