Knowledge base
dns-attemptsimportantWritten by the HubdirectiveHow many times a query is retried before the domain counts as unresolvable.dns-nameserverimportantWritten by the HubdirectiveName servers the engine queries, overriding whatever the system's resolver configuration says.dns-capacityWritten by the HubdirectiveHow many DNS operations may be outstanding at once.dns-intervalWritten by the HubdirectiveSeconds before an unanswered query is sent again.dns-min-ttlWritten by the HubdirectiveLower bound on cached lifetime: records with a shorter TTL are still kept this long, so that domains publishing very short TTLs cannot force a lookup per message.dns-rotateWritten by the HubdirectiveWhether queries are distributed across the configured name servers instead of always preferring the first.dns-timeoutWritten by the HubdirectiveSeconds the resolver waits for a reply after its last attempt before giving up.dns-buffersizeWritten by the HubdirectiveSize of the socket buffer used for DNS traffic.dns-socketsWritten by the HubdirectiveHow many sockets the resolver spreads its queries across.Why the resolver is a delivery concern, not an infrastructure detailimportantWritten by the HubmechanismA failed lookup is a permanently failed message, so the resolver a node uses is part of its deliverability, not part of its plumbing.DNS overridesWritten by the Hubconsole screenPins a hostname to a chosen address, bypassing the resolver — and hides behind another screen.dnsdatabase tablePins a hostname to an address, bypassing resolution for that name.The destination could not be resolvedcriticaldelivery stateNo address could be found for the destination; the result field says whether the address is to blame or our own resolver is.