50 network+ practice test Practice Questions: Question Bank 2025

A technician is asked to ensure that users on a guest Wi-Fi network cannot access internal servers but can still reach the internet. Which solution BEST meets this requirement?

A network engineer needs to reduce broadcast traffic and improve performance by separating a flat network into multiple logical networks without changing the physical cabling. What should the engineer implement?

Which port is typically used by clients to obtain an IP address from a DHCP server?

A user reports slow performance when accessing a web application hosted on a remote network. The WAN link is not saturated, but packet capture shows frequent retransmissions. Which issue is MOST likely causing the problem?

An organization wants to ensure that only company-managed laptops can connect to the corporate wireless network. Users should authenticate with individual credentials, and devices should be validated before being granted access. Which solution BEST meets these requirements?

A network administrator needs to prevent a rogue switch from becoming the root bridge in a Layer 2 environment. Which switch feature should the administrator enable on access ports?

A small branch office needs automatic failover between two ISPs. The requirement is to keep a consistent default gateway for users on the LAN while enabling the edge routers to provide redundancy. Which technology BEST fits this design?

After adding a new subnet, users report that internal hostnames intermittently fail to resolve, but direct queries to the DNS server by IP work. The DNS server logs show many queries with "SERVFAIL" during peak hours. Which change is the MOST likely fix?

A company is implementing a site-to-site VPN between two offices. The security team requires confidentiality, integrity, and protection against replay attacks at the IP layer for all traffic between sites. Which technology should be used?

A new access switch has been installed. End devices can communicate within their VLAN, but devices in VLAN 20 cannot reach devices in VLAN 30. The router-on-a-stick configuration appears correct, and the router subinterfaces are up. Which issue is MOST likely on the switch uplink to the router?

A small office wants to prevent users on the guest Wi-Fi from accessing internal file servers while still allowing internet access. Which configuration best meets this requirement?

An administrator needs to ensure that all devices on a wired network automatically receive an IP address, default gateway, and DNS server settings. Which service provides this functionality?

A technician must verify that a switch port is negotiating the expected speed and duplex. Which interface is MOST appropriate to check first?

A company is migrating to IPv6. The ISP provides an IPv6 /48 allocation, and the company wants a separate /64 for each VLAN. Which plan is MOST appropriate?

A network engineer needs to reduce broadcast traffic and improve security by limiting which devices can communicate directly at Layer 2. Which solution BEST addresses this goal?

After a power outage, several switches come back online with incorrect timestamps, causing certificate validation failures for management access. Which solution should be implemented to prevent this in the future?

A technician connects a laptop to a switch port configured as an 802.1Q trunk. The laptop receives no IP address from DHCP. The trunk allows VLANs 10, 20, and 30, and DHCP for VLAN 20 is working for other clients. Which is the MOST likely cause?

A security team wants to ensure that only corporate-managed devices can connect to the wired network, using user/device authentication before a port becomes active. Which technology BEST meets this requirement?

A campus network must support a new latency-sensitive voice deployment. During peak hours, voice quality degrades due to congestion. Which configuration is MOST appropriate to prioritize voice traffic end-to-end?

Users report that connections to an internal application intermittently fail. A packet capture shows repeated TCP SYN packets from clients with no SYN-ACK responses, but ICMP pings to the server succeed consistently. Which is the MOST likely cause?

An administrator is connecting a new access switch to a distribution switch using fiber. The switch ports support 1Gb and 10Gb, but the link is only negotiating at 1Gb. Which of the following is the MOST likely cause?

A network engineer wants to prevent a rogue DHCP server from handing out IP addresses on a user VLAN. Which feature should be enabled on the access switches?

Which of the following IPv6 addresses is a link-local address?

Users report that VoIP calls sound choppy during large file transfers. The WAN link is not saturated, but packet loss and jitter increase during backups. Which configuration change would MOST directly improve call quality?

A server is dual-homed to two different switches for redundancy. The server team reports intermittent connectivity and duplicate frames. Switching loops are not observed elsewhere. Which server-side configuration is MOST likely causing the issue?

A company is replacing an aging hub-and-spoke WAN with a design that allows each branch to use both broadband and LTE links and dynamically choose the best path for applications. The company also wants centralized policy control. Which solution BEST fits these requirements?

A security administrator needs to reduce the chance of VLAN hopping attacks on a switch. Which configuration is the BEST practice on access ports?

A network engineer must connect two buildings that are 4km apart. The link needs 10Gb throughput and must be resistant to electromagnetic interference. Which cabling solution is MOST appropriate?

A company wants to restrict outbound traffic so that internal hosts can only access the internet using HTTP/HTTPS, while also minimizing the number of publicly routable IP addresses required. Which combination of technologies BEST meets these requirements?

After a routing change, users in VLAN 20 cannot reach a server in VLAN 30. A technician verifies both VLANs exist and inter-VLAN routing is enabled. The server in VLAN 30 can reach its default gateway, but hosts in VLAN 20 cannot ping VLAN 30's gateway. Which issue is the MOST likely cause?

A network administrator needs a Layer 2 mechanism to prevent loops in a switched network while still allowing redundant links. Which technology should be enabled?

A technician is asked to assign a static IP to a new printer. The printer must keep its address after reboots and should be easy to find later in DNS by name. Which record type is MOST directly used to map the printer name to its IP address?

A user reports they can access internal websites by IP address but not by hostname. Other users on the same LAN can resolve hostnames normally. Which is the MOST likely issue on the user's workstation?

A company wants to reduce the chance of unauthorized devices joining the corporate Wi-Fi. Which option provides the BEST authentication method for enterprise wireless networks?

A small branch office needs to provide separate networks for employees and guest Wi-Fi using the same switch infrastructure. The guest network must not access internal resources. Which solution BEST meets this requirement?

A network engineer is implementing link aggregation between a switch and a server to increase throughput and provide redundancy. Which configuration should be used to negotiate and manage the aggregated links?

A network operations team wants to automatically detect failing switch ports and quickly alert on interface errors (e.g., increasing CRC errors) using a centralized monitoring system. Which protocol is MOST appropriate to collect interface counters and health metrics?

Users complain that voice quality is poor during large file transfers on the same network segment. The switch supports QoS. Which action would BEST improve voice quality?

A company uses an always-on site-to-site VPN between two offices. One location recently changed its ISP, and now the tunnel intermittently fails during peak hours. Logs show frequent rekey events and dropped packets, but internal routing is stable. Which is the MOST likely cause?

A security engineer needs to allow remote users to access internal web applications without placing those users directly on the internal network. The solution must enforce user authentication and provide application-level access rather than full network access. Which solution BEST fits these requirements?

A technician needs to verify whether a switch port is negotiating the correct speed and duplex with an attached workstation. Which command on the switch is MOST appropriate?

A network engineer needs to prevent lateral movement between devices in the same guest wireless SSID while still allowing guests to reach the internet. Which feature should be enabled on the wireless network?

A branch office is migrating to an ISP that delivers a single Ethernet handoff requiring PPPoE authentication. Which type of device configuration is MOST likely needed at the branch edge?

A user reports that internal web applications work by IP address but not by hostname. Internet browsing works normally. Which service is MOST likely misconfigured for the user?

A company wants to connect two sites over the internet using an encrypted tunnel. They also need dynamic routing to fail over between two ISPs at each site. Which solution BEST meets these requirements?

A switch has multiple VLANs and must forward traffic between them. The existing router is underpowered. Which design change is MOST appropriate to improve inter-VLAN performance?

After a power outage, several switches come back online and users report intermittent connectivity and high latency. A technician suspects a Layer 2 loop. Which observation MOST strongly supports this suspicion?

A security team wants to reduce the risk of an on-path attacker intercepting management traffic to network devices. Which change is the BEST practice for device administration?

A network uses a dynamic routing protocol. An engineer wants to ensure a specific path is preferred for outbound traffic from Site A to a remote network, without changing link bandwidth. Which approach is MOST appropriate?

A company deploys IPv6 internally. Some hosts can reach external IPv6 sites, but others cannot. All hosts have valid global unicast IPv6 addresses and correct default gateways. The failure only occurs for hosts on one VLAN. Which issue is the MOST likely cause?