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. 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. 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?
1. Retry interval
2. Minimum (default) TTL
3. Refresh interval
4. Expires after
Answer: Pending
Answer is – 4. Expires after
https://msdn.microsoft.com/en-us/library/bb727018.aspx
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.
Sorry sri, But is that TTL is DNS cache duration….?
look at this, the answer is 4
http://www.dslreports.com/forum/r10581272-BIND-Difference-between-TTL-and-SOA-val-EXPIRE
2. Modify the TTL (Change it to 3 days).
Serial number
This is the “version number” of this database file. It increases each time the database file is changed.
Refresh time
The amount of time (in seconds) that a secondary server will wait between checks to its master server to see whether the database file has changed and a zone transfer should be requested.
Retry time
The amount of time (in seconds) that a secondary server will wait before retrying a failed zone transfer.
Expiration time
The amount of time (in seconds) that a secondary server will spend trying to download a zone. Once this time limit expires, the old zone information will be discarded.
Time to live
The amount of time (in seconds) that another DNS server is allowed to cache any resource records from this database file. This is the value that is sent out with all query responses from this zone file when the individual resource record doesn’t contain an overriding value.
http://www.peerwisdom.org/2013/05/15/dns-understanding-the-soa-record/
“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).”
It is Expires after, TTL is for resource records.
It’s 3. Refresh interval.
Answer is absolutely 4 as sultan stated.
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