302 sample questions

Question 1

A financial enterprise is migrating its global application delivery infrastructure to F5 BIG-IP DNS. The architecture team needs to understand how DNS queries will flow from end users to the BIG-IP DNS listeners to ensure proper security and routing configurations.

The enterprise currently uses a mix of internal caching resolvers and external public DNS services. The security team has mandated that BIG-IP DNS must not perform recursive lookups for external domains to prevent potential DNS amplification attacks.

In a standard DNS query dataflow where a client queries a public domain hosted on the BIG-IP DNS, how does the BIG-IP DNS handle the resolution process, and what is the primary difference between iterative and recursive queries in this context?

Accepted Answer

The client's Local DNS (LDNS) performs recursive queries on behalf of the client. The BIG-IP DNS receives iterative queries from the LDNS and responds authoritatively without querying other servers.

Answer

The BIG-IP DNS acts as a recursive resolver by default, querying root servers on behalf of the client. An iterative query requires the client to do the work.

Answer

The BIG-IP DNS receives recursive queries directly from the end user's browser and performs iterative queries to backend LTM servers to resolve the IP address.

Answer

Iterative queries are used exclusively for zone transfers between BIG-IP DNS devices, while recursive queries are used for client resolution.

Question 2

A government agency requires all public-facing DNS zones to be secured using DNSSEC to prevent DNS spoofing and cache poisoning. When configuring BIG-IP DNS to sign these zones, which TWO of the following resource record types are automatically generated and used to establish the chain of trust and verify the authenticity of the response? (Select TWO)

Accepted Answer

RRSIG

Accepted Answer

DNSKEY

Answer

SOA

Answer

PTR

Question 3

True or False: In BIG-IP DNS ZoneRunner, a 'Stub' zone contains only the SOA, NS, and A records necessary to identify the authoritative servers for that zone, whereas a 'Hint' zone is used to find the root servers of the DNS namespace.

Accepted Answer

True

Answer

False

Question 4

An administrator is configuring topology-based load balancing on a BIG-IP DNS system. They need to route traffic based on the geographic location of the client making the request. Based on standard DNS architecture, which source IP address will the BIG-IP DNS evaluate against its topology records when it receives the query?

```mermaid
graph TD
Client[Client IP: 203.0.113.5] --> LDNS[LDNS IP: 198.51.100.10]
LDNS --> Root[Root Servers]
LDNS --> GTM[BIG-IP DNS Listener: 201.10.10.1]
```

Accepted Answer

The LDNS IP: 198.51.100.10

Answer

The Client IP: 203.0.113.5

Answer

The BIG-IP DNS Listener IP: 201.10.10.1

Answer

The IP address of the Root Servers

Question 5

A network engineer is configuring a BIG-IP DNS listener to support an environment transitioning to IPv6. The organization currently only has IPv4 routing configured to the BIG-IP DNS appliance, but clients are requesting IPv6 addresses for backend web servers. Which statement accurately describes how BIG-IP DNS handles this scenario?

Accepted Answer

BIG-IP DNS can receive a query for an AAAA record over an IPv4 transport network and return an IPv6 address in the response.

Answer

BIG-IP DNS requires an IPv6 listener (IPv6 transport) to answer AAAA queries.

Answer

BIG-IP DNS will drop AAAA queries if they arrive on an IPv4 listener.

Answer

DNS6to4 must be enabled on the DNS profile for BIG-IP DNS to parse AAAA queries over IPv4.

Question 6

When defining GTM objects, what is the primary purpose of configuring a 'Prober Pool' in BIG-IP DNS?

Accepted Answer

To explicitly define which BIG-IP systems (running big3d) are allowed to perform health monitoring for specific generic servers.

Answer

To group multiple BIG-IP DNS devices into a sync group for configuration replication.

Answer

To serve as a fallback pool of virtual servers when the primary Wide IP pool fails.

Answer

To aggregate DNS metrics and performance statistics for reporting purposes.

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Free 302 sample questions

True or False: In BIG-IP DNS ZoneRunner, a 'Stub' zone contains only the SOA, NS, and A records necessary to identify the authoritative servers for that zone, whereas a 'Hint' zone is used to find the root servers of the DNS namespace.

When defining GTM objects, what is the primary purpose of configuring a 'Prober Pool' in BIG-IP DNS?

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