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| The following features are new or changed in <var class="product">[[Janus TCP/IP Base]]</var>.
| | Content moved to M204int page of same name, but history preserved here. |
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| ==DNS Retries==
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| Prior to <var class="product">[[Sirius Mods]]</var> Version 7.8,
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| the <var>[[JANUS NAMESERVER]]</var> command had no facility to call for a retry of
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| a DNS UDP packet for which no response is received.
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| This meant that if <var class="product">Janus</var> does a DNS lookup just when the target nameserver
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| is down for an instant, or if the UDP packet gets lost on the network (IP
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| networks don't have to guarantee delivery of IP packets), the DNS lookup
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| could fail.
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| The version 7.8 "DNS Retries" feature is
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| a <var>RETRIES</var> parameter for the <var>JANUS NAMESERVER</var> command.
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| Setting <var>RETRIES</var> to a positive integer value, say 2, instructs <var class="product">Janus</var>
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| to retry as many as two times if no response was received to a DNS lookup.
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| Setting <var>RETRIES</var> to 0, its default, means no retries are attempted.
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| On a swamped network, it is probably better to
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| set a <var>JANUS NAMESERVER TIMEOUT</var> value of, say, 3 and a <var>RETRIES</var> setting of 2, rather than to set <var>TIMEOUT</var> to 10 with <var>RETRIES</var> at 0. This is so because:
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| *If a packet gets dropped, there is no benefit to waiting 10 seconds instead of 3.
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| *It is very unlikely that it would take a nameserver 3 seconds to respond to a received request (including packet turnaround time).
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| It probably does not make sense to set <var>RETRIES</var>
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| to a value greater than 2: if packets are being dropped so frequently
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| that three consecutive DNS requests are dropped, you have problems much more serious than the failed lookups.
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| {{Template:Content index: V7.8 Release Notes}}
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