* James Stevens: > Health-checks (e.g. pingdom etc) with RD=1 seem pretty common.
They do not work reliably because failure rates for some large authoritative servers with RD=1 are significantly higher than with RD=0 (or at least were about ten years ago). I remember a bug in monitoring software which reported sporadic failure for perfectly healthy servers, and it turned out that the cause was a bug where the software sent RD=1 queries instead of RD=0 queries. The failure was stochastic, though. It oculd have been software or configuration divergence a cluster behind a load balancer But if I recall correctly, the failure rate was quite a bit lower than that, so there was probably another factor involved. Thanks, Florian _______________________________________________ dns-operations mailing list [email protected] https://lists.dns-oarc.net/mailman/listinfo/dns-operations
