default local DNS caching name server
P J P
pj.pandit at yahoo.co.in
Sat Apr 12 11:56:58 UTC 2014
> On Saturday, 12 April 2014 4:55 PM, William Brown wrote:
> This isn't how DNS works ..... You populate your cache from the ISP, who
> queries above them and so on up to the root server.
Hmmn. There are two ways a local resolver can be configured. One is it contacts root servers and builds its cache from their responses. That's recursive name resolution. And second is it acts like a stub resolver and forwards client queries to another recursive resolver.
N-DJBDNS supports both these options. Maybe you could install it and see for yourself.
try -> # yum install ndjbdns
> I should clarify. I cache the record foo.work.com from the office, and
> it resolves differently externally. When I go home, it no longer
> resolves to the external IP as I'm using the internally acquired record
> from cache.
No. Your foo.work.com address does not resolve to a public internet address, but resolves to an internal company specific address. And when you come home, your domain foo.work.com still resolves to the _same_ internal address, but you are unable to connect to it because you are outside of the office network.
Try connecting over VPN connection from home.
> A local cache will help you with 1 "sometimes" provided you get the
> first record back once.
> It won't prevent the second or third as you will just cache the
> incorrect data instead (Provided you clear cache on network change, this
> isn't a problem ... it just means you hold onto bad data for that
> session for longer, which creates other issues.)
> I personally am actually against DNS cache on systems as it tends to
> create more problems than it solves.
Maybe you could try N-DJBDNS -> # yum install ndjbdns
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