Your company has a main office and a branch office.
The network contains an Active Directory domain named contoso.com.
The main office contains a domain controller named DC1 that runs Windows Server 2012
R2. DC1 is a DNS server and hosts a primary zone for contoso.com. The branch office
contains a member server named Server1 that runs Windows Server 2012 R2. Server1 is a
DNS server and hosts a secondary zone for contoso.com.
The main office connects to the branch office by using an unreliable WAN link.
You need to ensure that Server1 can resolve names in contoso.com if the WAN link in
unavailable for three days.
Which setting should you modify in the start of authority (SOA) record?
A.
Retry interval
B.
Refresh interval
C.
Expires after
D.
Minimum (default) TTL
Explanation:
Used by other DNS servers that are configured to load and host the zone to determine when
zone data expires if it is not renewed
C
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Saad, you’re USELESS!
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hhhhhhhhhh
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C.
Expire interval- Used by other DNS servers that are configured to load and host the zone to determine when zone data expires if it is not renewed.
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Expires After – The period of time for which zone information is valid on the secondary server. If the secondary server can’t download data from a primary server within this period, the secondary server lets the data in its cache expire and stops responding to DNS queries. Setting Expires After to seven days allows the data on a secondary server to be valid for seven days.
• Minimum (Default) TTL – The minimum time-to-live value for cached records on a secondary server. The value is set in the format Days : Hours : Minutes : Seconds. When this value is reached, the secondary server expires the associated record and discards it. The next request for the record will need to be sent to the primary server for resolution. Set the minimum TTL to a relatively high value, such as 24 hours, to reduce traffic on the network and increase efficiency. However, keep in mind that a higher value slows down the propagation of updates through the Internet.
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So if the TTL is 24 hours and the secondary server loses its connection to the primary server, the secondary server expires the record and discards it after 24 hours has lapsed. So there is no record left to expire even if Expires After is set to 7 days. That cached record is gone, right?
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I was think the exact same thing.
You should change both settings in my opinion. ?:) – 🙁 – :'(
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C:
Expires After The period of time for which zone information is valid on the secondary server. If the secondary server can’t download data from a primary server within this period, the secondary server lets the data in its cache expire and stops responding to DNS queries. Setting Expires After to seven days allows the data on a secondary server to be valid for seven days.
https://msdn.microsoft.com/en-us/library/bb727018.aspx
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EXPIRE: Expiry Interval
Time in seconds that a secondary name server will treat its zone file as valid when the primary name server cannot be contacted. If your primary name server goes offline for some reason, you want the secondary name names to keep answering DNS queries for your domain until you can get the primary back online. Make this value too short and your domain will disapear from the Internet before you can bring the primary back online. A good value would be something between 2 weeks (1209600 seconds) and 4 weeks (2419200 seconds).
If you stop using a domain and delete it from the configuration of the primary name server, remember to remove it from the secondary name servers as well. This is especially important if you use third-party secondary name servers since they will continue to answer queries for the deleted domain — answers which could now be completely incorrect — until the expiry interval is reached.
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