gluon/docs/features/dns-cache.rst

DNS-Caching
===========
User experience may be greatly improved when dns is accelerated. Also, it
seems like a good idea to keep the number of packages being exchanged
between node and gateway as small as possible. In order to do this, a
dns-cache may be used on a node. The dnsmasq instance listening on port
53 on the node will be reconfigured to answer requests, use a list of
upstream servers and a specific cache size if the options listed below are
added to site.conf. All settings are optional, though if no dns server is
set, the configuration will not be altered by gluon-core.

Besides caching dns requests from clients, the next_node-addresses are set to
resolve to a configurable name that may optionally be placed in next_node.name.

::

  dns = {
    cacheentries = 5000,
    servers = { '2001:db8::1', },
  },
  
  next_node = {
    name = 'nextnode',
    ip6 = '2001:db8:8::1',
    ip4 = '198.51.100.1',
  }


The cache will be initialized during startup.
Each cache entry will occupy about 90 bytes of RAM.