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Free Online Flashcard Deck

3 DNS Configuration and Troubleshooting Free Online FlashCards

Study 3 DNS Configuration and Troubleshooting with 12 free online flashcards. Review key terms, definitions, and concepts with this interactive flashcard deck.

12 cards
01
Front

How do a resolver and an authoritative name server differ?

Back

A resolver asks DNS questions on behalf of a client; an authoritative name server answers from the zone data it manages.

02
Front

What do A and AAAA records map?

Back

A and AAAA records map a name to an IPv4 address and an IPv6 address, respectively.

03
Front

What does a CNAME record do?

Back

A CNAME makes one name an alias of another canonical name; it is not an address record.

04
Front

What information does an MX record provide?

Back

An MX record identifies a domain’s mail server and includes a preference value.

05
Front

What key information does an SOA record contain?

Back

An SOA record marks the zone’s start and includes its primary server, contact, serial number, and timing values.

06
Front

What does a PTR record map?

Back

A PTR record maps an address to a name in a reverse-lookup zone.

07
Front

How does TTL affect DNS caching?

Back

TTL controls how long resolvers may cache a record. Lowering it before a planned change can reduce how long old answers persist.

08
Front

What record-placement restrictions apply to CNAMEs?

Back

Do not place other record types at the same name as a CNAME. Use A or AAAA records, rather than a CNAME, for a zone apex.

09
Front

How can a DNS suffix search list affect short-name lookups?

Back

A suffix search list can expand a short name such as web to web.example.com. Test the fully qualified name separately to distinguish suffix issues from missing records.

10
Front

What does dig +trace show?

Back

dig +trace follows the delegation path from the DNS root toward the requested name.

11
Front

What flag indicates an authoritative DNS answer?

Back

For a direct, nonrecursive query to an authoritative server, the answer should have the AA flag.

12
Front

How do NXDOMAIN and NOERROR with no requested record differ?

Back

NXDOMAIN means the responding server says the queried name does not exist. NOERROR with no requested record means the name may exist but not with that record type.