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> no mainstream consumer OS runs a local recursive resolver I think Windows might do something close. DNS client requests are cached on a per-machine basis thr
by asveikau 7y ago
> no mainstream consumer OS runs a local recursive resolver
I think Windows might do something close. DNS client requests are cached on a per-machine basis through the DnsCache NT service. But I do not think getaddrinfo() and friends talk to that service via DNS, so strictly speaking it is not a recursive DNS server, though the resulting behavior is largely the same as if it were.
- akerl_ 7y agoI think there’s a differentiation here between a local DNS cache (which does exist on some consumer operating systems) and a local recursive resolver. The former lets the system reach out to an upstream resolver and caches the results. By contrast, a recursive resolver is responsible for starting at the root zone and recursing downward from there to resolve the requested domain (so when processing a query for “foo.example.org”, the recursive resolver queries “org”, then uses the NS records returned to query “org.example”, then uses the returned NS records to query “org.example.foo”)
- asveikau 7y agoYeah ok, that's a difference I hadn't thought of. In most local caching servers the next hop is going to be the ISP or similar, rather than going to the root.