Override transferred zone information?
kcd at daimlerchrysler.com
Fri Jan 5 01:20:59 UTC 2007
Eric Jain wrote:
> Just found the GeoDNS patch, seems like a great solution to a problem we
> have (people linking to and bookmarking mirror web sites).
> There is one problem, though: We use an external secondary DNS server
> (easyDNS.com), which does not support GeoDNS. easyDNS uses automatic zone
> transfers to keep itself up to date, so I was wondering if it is possible
> to get BIND to return fallback zone information that easyDNS can understand
> (e.g. a simple round robin setup on the secondary DNS would be fine)?
"Simple round robin" isn't going to give you the "geo" functionality you
seem to be striving for.
Not sure what you mean by "fallback zone information" either. There's no
way within the protocol to say "prefer answers for a given zone from
this set of nameservers, otherwise fall back to this other set". Is that
what you meant? Unfortunately, iterative resolvers will typically prefer
*faster* nameservers over slower ones, so presumably the easyDNS servers
are getting a lot more queries for your zones than your own nameservers
are (if not, perhaps you aren't getting your money's worth). Which
means, all other things being equal, even if you implement GeoDNS on
your servers, Internet clients will get the non-"geo"'ed answers more
often than not.
If you want to provide the "geo" functionality in any consistent way, I
think you need to *force* the answers to come from your own
authoritative nameservers rather than the easyDNS ones. You could
accomplish this by either taking your whole zone(s) in-house from
easyDNS or by just delegating certain subzones from easyDNS-managed
zones, e.g. delegate www.example.com from example.com, and run those
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