Wireless Modem Router: What is prefetching of name resolution

What is prefetching of name resolution
What does a Prefetching name resolutions process actually does in a dns. I am trying to get information the name caching issue of a dns system. How does this process work. I need a detailed overview of that. I need the process of implementing prefetching and refreshing the same. What is needed in the same and what are the negative points of the same.
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#2
Old 16-02-2010
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Re: What is prefetching of name resolution
As the Internet grows, there is a bound to the accumulation hit rate a resolver can reach with regular, passive caching, there are comparatively few very popular names, and caching the unpopular ones doesn't help much, since they finish before they are demanded again. On the other hand, you would like to be able to serve less accepted, less repeatedly demanded names as rapidly as you can serve any popular names. Since it's not satisfactory to serve stale or extrapolated results for those names, we also necessitate to guarantee that the resolutions are always valid (i.e. have not passed the TTL expiry time).
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#3
Old 16-02-2010
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Re: What is prefetching of name resolution
To complete these goals, you are testing with insistently prefetching and refreshing names separately of whether and when users ask for them. There are two most important challenges to implementing prefetching appropriately. With regard to other nameservers capability limits. To guarantee that we do not overload other nameservers with prefetching questions, you can compel rate limits on our outgoing demands. To make sure that that self-imposed cap on outgoing capability is not exhausted by rogue traffic, you can separate the QPS-based quota for each of the nameservers into multiple traffic queues and strictly prioritize prefetching traffic over user traffic.
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#4
Old 16-02-2010
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Re: What is prefetching of name resolution
Managing our own servers capability limits. As our servers do not have unlimited memory and CPU, you necessitate to carefully select the names which we can prefetching. you can converse the challenges and your approaches to selecting names for prefetching below. In addition, to prevent the accumulation from being eaten up by bogus entries from attackers, you can divide the main accumulation into primary and secondary partitions and give read/write access to each partition according to traffic type.
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#5
Old 16-02-2010
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Re: What is prefetching of name resolution
To make the most of the use of the fixed nameserver-QPS bound you can have imposed, your necessitate to weigh the advantage of each name record against its cost (nameserver capability and local CPU and RAM), which is inversely proportional to its TTL. On the other hand, determining the advantage of a given name documentation is a complex task, as you would like to achieve all of the following, sometimes competing, goals.
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#6
Old 16-02-2010
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Re: What is prefetching of name resolution
Serving accepted names even when our servers are under DoS assaults that are arduous our outbound capability. This implies that you be supposed to, in fact, prefetching accepted names. Avoiding bogus names inserted by deliberate pollution attacks. This implies that you cannot rely on solely on user traffic as the source of names to select.
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