CCNA Network Services and Security — 10 Questions

Question 1

What does switchport port-security primarily protect against on an access port?

Accepted Answer

Unauthorized MAC addresses appearing on the port. Port security limits which MAC addresses can use an access port, helping prevent rogue endpoint attachment and simple CAM table abuse.

Answer

OSPF route flapping

Answer

DNS spoofing across the enterprise

Answer

Wireless rogue APs on every VLAN

Question 2

What is the primary purpose of NTP in a routed network?

Accepted Answer

To synchronize device clocks. Network Time Protocol is used to keep device clocks synchronized. Accurate time is especially important for logs, troubleshooting, certificates, and coordinated events across devices.

Answer

To encrypt management traffic

Answer

To resolve hostnames into IP addresses

Answer

To assign IP addresses dynamically

Question 3

What is the primary function of DNS?

Accepted Answer

To map hostnames to IP addresses. DNS resolves hostnames to IP addresses and can also support reverse lookups and other naming records. It is a foundational naming service for IP networks.

Answer

To translate MAC addresses into switchport numbers

Answer

To assign default gateways to hosts

Answer

To maintain STP topology information

Question 4

What is the main purpose of a syslog server in a network?

Accepted Answer

To collect and store log messages from devices. A syslog server centralizes event and log messages from network devices, which helps with monitoring, troubleshooting, auditing, and incident response.

Answer

To allocate DHCP leases

Answer

To maintain a synchronized routing table

Answer

To translate private addresses to public addresses

Question 5

What is the main benefit of Port Address Translation (PAT)?

Accepted Answer

It allows many internal hosts to share one public IPv4 address. PAT conserves public IPv4 space by translating multiple inside hosts to a single public address, distinguishing sessions by port numbers.

Answer

It encrypts all traffic leaving the LAN

Answer

It removes the need for private IP addressing

Answer

It replaces routing protocols

Question 6

What does the confidentiality objective of the CIA triad focus on?

Accepted Answer

Preventing unauthorized disclosure of information. Confidentiality is about preventing unauthorized disclosure of information.

Answer

Preventing unauthorized changes to data

Answer

Ensuring systems are reachable when needed

Answer

Providing authentication and accounting only

Question 7

What is the main function of DNS in an IP network?

Accepted Answer

It resolves hostnames to IP addresses.. DNS resolves human-readable names to IP addresses and can also store related records.

Answer

It assigns IP addresses to clients automatically.

Answer

It encrypts application traffic end to end.

Answer

It advertises default routes to routers.

Question 8

What is the main purpose of an allowlist-based firewall policy compared with a denylist-based one?

Accepted Answer

It permits only explicitly approved traffic patterns.. An allowlist permits only explicitly approved traffic and denies everything else by default, which is generally more restrictive.

Answer

It allows all traffic except a few known bad flows.

Answer

It automatically encrypts all allowed traffic.

Answer

It disables the implicit deny at the end of the ACL.

Question 9

What does the second 'A' in AAA stand for?

Accepted Answer

Authorization. AAA stands for Authentication, Authorization, and Accounting. The second “A” is Authorization. In plain language, authentication answers the question “Who are you?” Authorization answers “What are you allowed to do?” and accounting answers “What did you do?” Those three ideas work together to control and track access to devices and services.

This question is simple, but it matters because many security designs depend on keeping those functions separate in your mind.

Answer

Authentication

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Availability

Answer

Accounting

Question 10

Which statement best describes the role of DNS in a network?

Accepted Answer

DNS resolves names into IP-related information. DNS helps devices and users resolve names into IP-related information. In plain language, it means people can use easy-to-remember hostnames instead of typing numeric IP addresses every time they want to reach a server or service. This makes networks more usable and easier to manage, especially when addresses change but names remain stable.

DNS does not assign addresses the way DHCP does, and it does not synchronize time like NTP. It also is not a routing protocol. Its job is name resolution. That is a fundamental service concept and a very common CCNA test point because many practical network symptoms can be traced back to name-resolution failures even when basic IP connectivity still works.

Answer

DNS dynamically assigns client IP addresses

Answer

DNS prevents switching loops on VLAN trunks

Answer

DNS is the default metric used by OSPF