22042a3bf2
gluon-core: dns-cache documentation polish Now its clear that upstreams severs normally means "community gateways". * added cacheentries to description * made upstream server description more general * description of the A and AAAA-records for next_node added * mention of Cache not being allocated when not set in site.conf * dns-cache doku polish
41 lines
1.4 KiB
ReStructuredText
41 lines
1.4 KiB
ReStructuredText
DNS-Caching
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===========
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User experience may be greatly improved when dns is accelerated. Also, it
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seems like a good idea to keep the number of packages being exchanged
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between node and gateway as small as possible. In order to do this, a
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dns-cache may be used on a node. The dnsmasq instance listening on port
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53 on the node will be reconfigured to answer requests, use a list of
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upstream servers and a specific cache size if the options listed below are
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added to site.conf. Upstream servers are the DNS servers which are normally
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used by the nodes to resolve hostnames (e.g. gateways/supernodes).
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There are the following settings:
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servers
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cacheentries
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If both options are set the node will cache as much DNS records as set with
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'cacheentries' in RAM. The 'servers' list will be used to resolve the received
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DNS-queries if the request cannot be answered from cache.
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If these settings do not exist, the cache is not intialized and RAM-usage will not increase.
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When next_node.name is set, an A-record and an AAAA-record for the
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next-node-IP are placed in the dnsmasq configuration. This means that the content
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of next_node.name may be resolved even without upstream connectivity.
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::
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dns = {
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cacheentries = 5000,
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servers = { '2001:db8::1', },
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},
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next_node = {
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name = 'nextnode',
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ip6 = '2001:db8:8::1',
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ip4 = '198.51.100.1',
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}
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The cache will be initialized during startup.
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Each cache entry will occupy about 90 bytes of RAM.
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