All practice questions

A network technician needs to trace an unlabeled copper UTP cable run from a wall jack in a user's office to its corresponding port on a patch panel in the telecommunications closet. Which of the following diagnostic tools is best suited for this task?

A network technician is troubleshooting a switch-to-switch trunk link that is dropping traffic. Reviewing the switch console logs reveals a native VLAN mismatch error, while interface statistics report high numbers of late collisions. Which TWO configuration actions should the technician take to resolve these issues? (Select TWO.)

A network administrator is troubleshooting host reachability issues on an enterprise dual-stack network. Workstations cannot connect to an internal server using its hostname `app.internal.example.com`, though direct IPv6 ping tests succeed. The administrator executes the following troubleshooting command from a client system:

C:\> nslookup app.internal.example.com
Server: dns01.internal.example.com
Address: 10.0.0.53

*** dns01.internal.example.com can't find app.internal.example.com: Non-existent domain

Next, the administrator runs `nslookup -type=AAAA app.internal.example.com`, which successfully returns the IPv6 address `2001:db8:85a3::8a2e:370:7334`.

Which of the following is the root cause of the initial resolution failure?

A network technician needs to isolate administrative access for core switches situated in an unstaffed facility. The security policy dictates that remote administrative management traffic must be completely separated from user data traffic so that compromised production host networks cannot reach the switch management interfaces. Which of the following strategies best fulfills this security requirement?

A server located at a remote branch office experiences a severe kernel panic, causing its host operating system to crash completely and lose network connectivity. An engineer needs to remotely inspect the server's POST output, modify BIOS/UEFI settings, and reinstall the operating system without traveling to the site. Which solution provides the hardware-level console and display access required to perform these tasks?

Match each remote management tool or protocol to the operational scenario where it serves as the primary solution.

A network security analyst is updating incident classification guidelines for enterprise threat vectors. Match each network attack type on the left with its corresponding attack vector characteristics on the right.

A network engineer is configuring an extended Access Control List (ACL) on a stateless router interface. Client workstations on the internal subnet ($10.200.15.0/24$) can successfully transmit outgoing HTTPS requests ($TCP$ port $443$) to external web servers, but return web traffic is blocked by the inbound ACL. Which of the following configuration adjustments will allow internal clients to receive return HTTPS traffic from external servers while maintaining stateless security controls? (Select TWO.)

A network technician needs to inspect a newly terminated Category 6 UTP patch cable to confirm proper T568B pinout alignment and verify that there are no open or shorted conductor pairs. Which TWO of the following diagnostic tools are designed to verify conductor continuity and pinout arrangement on copper twisted-pair cables?

A network administrator installs a new set of IP phones on a dedicated voice VLAN (VLAN 40). The enterprise DHCP server resides on VLAN 10. The phones fail to obtain IP addresses and automatically configure APIPA addresses instead. Which TWO of the following resolution actions or diagnostic steps should the technician perform to troubleshoot and resolve this issue? (Select TWO)

A network engineer is troubleshooting a newly deployed 10GBASE-LR single-mode optical fiber link between two distribution switches spaced 2 kilometers apart. An optical power meter registers an excessive loss of $14\text{ dB}$ across the link, significantly exceeding the maximum insertion loss budget of $2.5\text{ dB}$, despite both transceiver end-face connectors passing visual inspection with a fiber microscope. Which diagnostic tool should the engineer utilize to measure reflections and pinpoint the precise location and cause of the attenuation fault along the fiber run?

Match each command-line network utility on the left with its primary diagnostic function on the right.

A network engineer is troubleshooting reachability issues for a newly provisioned monitoring server located in an enterprise branch office. The server is assigned the static IP address $10.64.36.195$ with a subnet mask of $255.255.255.192$ ($/26$). The default gateway configured on the server interface is $10.64.36.129$. The server can successfully ping its own IP address, but all attempts to reach the default gateway or remote networks fail with a destination host unreachable error. Which of the following identifies the root cause of this connectivity failure?

A systems engineer is troubleshooting an issue where corporate users cannot authenticate to an enterprise wireless network. The engineer established a theory that an expired SSL/TLS certificate on the RADIUS server was causing EAP-TLS handshake failures and confirmed this theory by analyzing RADIUS authentication failure logs. Which of the following actions should the engineer perform NEXT in accordance with the CompTIA troubleshooting methodology? (Select TWO.)

Match each wireless network troubleshooting scenario or signal anomaly to its primary underlying cause.

A network technician suspects that a workstation's local DNS resolver is returning cached, out-of-date IP addresses for an internal server. The technician needs to test name resolution by sending a DNS query directly to a specific authoritative name server rather than relying on the local resolver configuration. Which command-line utility should the technician use to perform this direct query?

A network engineer is troubleshooting why internal workstations cannot access a newly deployed secure internal portal at `vault.corp.local`. The engineer executes `dig vault.corp.local` on a client workstation and captures the following terminal output:

;; QUESTION SECTION:
;vault.corp.local. IN A

;; ANSWER SECTION:
vault.corp.local. 300 IN CNAME sec-srv01.corp.local.

;; ADDITIONAL SECTION:
sec-srv01.corp.local. 300 IN A 10.200.5.25

Next, the engineer remotely accesses the destination server (`10.200.5.25`) and runs `netstat -tuln`, which displays:

Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 10.200.5.25:8443 0.0.0.0:* LISTEN
udp 0 0 0.0.0.0:53 0.0.0.0:* LISTEN

When end users attempt to navigate to `https://vault.corp.local` using standard browser defaults, the request immediately fails with a "Connection Refused" error. Based on the command outputs provided, which root cause explains why clients are unable to connect?

An infrastructure engineer is analyzing network logs to determine why an application server located at $10.50.20.15$ cannot transmit syslog data to a remote log collector at $172.18.4.50$. The collector receives log streams using UDP port $514$. The engineer inspects the active router interface access control list (ACL):

text
Extended IP access list ENTERPRISE_OUT
10 permit tcp 10.50.20.0 0.0.0.63 host 172.18.4.50 eq 514
20 permit ip 10.50.20.0 0.0.0.63 10.50.0.0 0.0.255.255
30 deny ip any any

Which of the following identifies the root cause of this connectivity failure?

A network engineer is investigating an inter-switch trunk link issue between Switch-A and Switch-B. Console logs on Switch-A continuously report "%CDP-4-NATIVE_VLAN_MISMATCH: Native VLAN mismatch discovered on GigabitEthernet0/1 (50), with Switch-B GigabitEthernet0/1 (10)". Furthermore, hosts assigned to VLAN 50 on Switch-A are unable to reach services on VLAN 50 connected to Switch-B, and frame traffic is leaking into VLAN 10. Which TWO configuration actions must be performed to restore proper Layer 2 trunking and isolation? (Select TWO.)

A network administrator is reviewing the management plane configuration of core campus switches during a security hardening initiative. The organization requires encrypted remote management and secure system monitoring. Which TWO configuration actions should the administrator implement to meet these hardening requirements?