[dns-operations] NSCD for Linux/UNIX stub resolver failover?

[Matthew Pounsett]

On Apr 23, 2014, at 12:10 , Chuck Anderson <cra at WPI.EDU> wrote:

> On Tue, Apr 22, 2014 at 11:27:02PM -0400, Robert Edmonds wrote:
>> Chuck Anderson wrote:
>>> 2. Use a local DNS daemon on every server with forwarders configured
>>>   to the network's nameservers, and fix resolv.conf to 127.0.0.1.
>> 
>> I'll shamelessly admit that I do this on all my Debian systems, where
>> "apt-get install unbound resolvconf" results in exactly that
>> configuration.
> 
> Has anyone had good experiences with using NSCD to solve the DNS
> failover problem?

The last time I used solaris for anything it was running nscd by default.  I had mixed experiences with it.  It solved the resolver failover problem fairly well, but brought other issues along with it.  I found it tended to cache things longer than it was supposed to, crashed fairly frequently (reintroducing a cousin of the lookup failure problem that it was solving) and made cache clearing for “emergency” DNS changes more problematic by decentralizing the cache.  

Granted this was a long time ago (over ten years) so the stability and TTL respect problems may have been solved; and that last issue isn’t so much of an issue if we’re talking about home nets instead of larger installations.