dns-cache.rst 1.7 KB

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  1. DNS caching
  2. ===========
  3. User experience may be greatly improved when dns is accelerated. Also, it
  4. seems like a good idea to keep the number of packages being exchanged
  5. between node and gateway as small as possible. In order to do this, a
  6. DNS cache may be used on a node. The dnsmasq instance listening on port
  7. 53 on the node will be reconfigured to answer requests, use a list of
  8. upstream servers and a specific cache size if the options listed below are
  9. added to site.conf. Upstream servers are the DNS servers which are normally
  10. used by the nodes to resolve hostnames (e.g. gateways/supernodes).
  11. There are the following settings:
  12. servers
  13. cacheentries
  14. If both options are set the node will cache as much DNS records as set with
  15. 'cacheentries' in RAM. The 'servers' list will be used to resolve the received
  16. DNS queries if the request cannot be answered from cache.
  17. If these settings do not exist, the cache is not intialized and RAM usage will not increase.
  18. When next_node.name is set, an A record and an AAAA record for the
  19. next-node IP address are placed in the dnsmasq configuration. This means that the content
  20. of next_node.name may be resolved even without upstream connectivity. It is suggested to use
  21. the same name as the DNS server provides: e.g nextnode.yourdomain.net (This way the name also
  22. works if client uses static DNS Servers). Hint: If next_node.name does not contain a dot some
  23. browsers would open the searchpage instead.
  24. ::
  25. dns = {
  26. cacheentries = 5000,
  27. servers = { '2001:db8::1', },
  28. },
  29. next_node = {
  30. name = 'nextnode.yourdomain.net',
  31. ip6 = '2001:db8:8::1',
  32. ip4 = '198.51.100.1',
  33. }
  34. The cache will be initialized during startup.
  35. Each cache entry will occupy about 90 bytes of RAM.