51 lines
1.7 KiB
Markdown
51 lines
1.7 KiB
Markdown
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## ZONE05: SOA 'expire' minimum value
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### Test case identifier
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**ZONE05** SOA 'expire' minimum value
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### Objective
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The SOA expire value specifies for how long any secondary name server
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keeps the zone valid without any contact with the primary name server.
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This value should be greater than how long a major outage would
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typically last. The expire value should also be larger than the
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refresh and retry values, as described in section 3.3.13 in
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[RFC 1035](https://datatracker.ietf.org/doc/html/rfc1035), and clarified in
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section 2.2 of [RFC 1912](https://datatracker.ietf.org/doc/html/rfc1912).
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Setting the expire value low will increase the risk of any unwanted
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non-availability of the zone because of any failures in contacting
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the primary name server.
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The [RIPE-203](https://www.ripe.net/publications/docs/ripe-203) recommendation
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for the expire value is 1000 hours (roughly 41 days). Older DNSCheck code
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had a 7 day minimum value (604800 seconds), and this is the minimum
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value we recommend as an absolute minimum.
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### Inputs
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The domain name to be tested.
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### Ordered description of steps to be taken to execute the test case
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1. Retrieve the SOA record from a delegated name server for the domain.
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2. If the answer from step 1 is not authoritative, iterate step 1 until there is an authoritative answer.
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3. Retrieve the expire value and the refresh value from the SOA record.
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4. If the expire value is less than 604800 seconds (7 days), this test
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case fails.
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5. If the expire value is lower than the refresh value, this test case
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fails.
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### Outcome(s)
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If the expire value is less than 604800 seconds or if the expire value is
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lower than the refresh value, this test case fails.
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### Special procedural requirements
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None.
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### Intercase dependencies
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None.
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