>if one knew more about DNS, maybe the .in-addr.arpa thing >would be obvious...
that's what's the subject of DNS lookups to do a `reverse lookup'. it's really an ordinary lookup of specially-constructed names in a domain reserved for them. that's the DNS itself, nothing to do with Plan 9. dnsquery is mainly used interactively. i'm not sure you really want to do it inside ndb/dns itself, because it catches cases where client programs are confused (or have been confused) between domain names and IP addresses.
