Nameserver chain?

[Arvind Doraiswamy]

Hi,

More questions :) - when I query a domain and let's say there isn't a name server configured, so it gets an authoritative response from the parent domain where name servers are configured - is there a way for me to find out which name server from which domain actually responded?

Something equivalent to dig +trace <domain> .. not so much detail but part of it would be nice if available.

Thanks

Arvind

[Brian Candler]

In general, you're sending the query to a recursive (caching) nameserver.  It will respond from its cache if the answer is already there; and if not, it will go fetch the answer and populate the cache. But in either case, it does not keep a record of where it got it from.

So if you want to implement the equivalent of dig +trace, it's up to you to do it yourself, querying from the root and following delegations. It's quite tricky to get it right.

[Arvind Doraiswamy]

Good to know, thanks Brian :)