[collectd] frequent dns queries

[kcheek<span style="display: none;">.trailing-username</span>(a)<span style="display: none;">leading-domain.</span>umich.edu]

When running in server mode, collectd seems to generate a large amount
of dns queries unless client ip addresses are added to /etc/hosts.
Would it be easy to modify the code so it doesn't generate so many dns
queries? (cache the dns responses somehow, etc.)  With a relatively
small setup (about 25 clients), the collectd server here is generating
about 4000 dns requests per minute.

Adding entries to /etc/hosts isn't a huge burden, but one of the
things I really like about collectd is the low-maintenance and simple
configuration.  Needing to modify /etc/hosts seems to detract from
that advantage just a little bit, especially in larger installations.

-Kevin