220-1201 Practice Test 3 — 25 Questions

Question 1

A technician is troubleshooting a VoIP phone that intermittently drops calls. The phone uses SIP (Session Initiation Protocol) for signaling and RTP (Real-time Transport Protocol) for audio. Which ports are typically used by these protocols?

Accepted Answer

SIP: 5060, RTP: 16384-32767. SIP typically uses port 5060 (UDP or TCP) for signaling, and RTP uses a range of UDP ports (often 16384-32767) for audio streams. Port 80 is HTTP, port 443 is HTTPS, and port 1720 is H.323 (another VoIP protocol).

Answer

SIP: 80, RTP: 443

Answer

SIP: 1720, RTP: 5060

Answer

SIP: 443, RTP: 80

Question 2

A user needs to transfer files securely between two Linux servers over the internet. Which port should be allowed through the firewall for this purpose?

Accepted Answer

22. Secure file transfer between Linux servers typically uses SCP (Secure Copy) or SFTP (SSH File Transfer Protocol), both of which operate over SSH. SSH uses TCP port 22 by default, so allowing port 22 through the firewall enables encrypted authentication and data transfer. This is the correct choice because it provides confidentiality and integrity for the file transfer over the internet.

Answer

21

Answer

20

Answer

443

Question 3

A technician is configuring a new database server that needs to accept remote connections from client applications using the default port for MySQL. Which port should be opened in the firewall?

Accepted Answer

3306. MySQL uses port 3306 by default for client connections. Opening this port allows remote database access.

Answer

1433

Answer

1521

Answer

5432

Question 4

During a security audit, a technician discovers that an internal web server is responding on port 8080 instead of the standard HTTP port. What is the most likely reason for this configuration?

Accepted Answer

The server is configured as a web proxy or alternate HTTP server.. Port 8080 is commonly used as an alternate HTTP port, often for web proxy servers or secondary HTTP servers. This allows administrators to run a separate HTTP service without conflicting with the standard port 80, which is frequently used for caching proxies or development environments.

Answer

The server is running HTTPS on a non-standard port.

Answer

The server is running an FTP service.

Answer

The server is using a custom application protocol.

Question 5

A company wants to allow employees to securely access the corporate network from home using their laptops. Which network service should be deployed to provide encrypted remote access?

Accepted Answer

VPN. C is correct because a Virtual Private Network (VPN) creates an encrypted tunnel between the employee's laptop and the corporate network, typically using protocols such as IPsec or TLS. This ensures that all data transmitted over the public internet is confidential and integrity-protected, meeting the requirement for secure remote access.

Answer

DHCP

Answer

DNS

Answer

Port forwarding

Question 6

A company's web server is accessible from the internet, but users report that the website loads slowly. The server's public IP is 203.0.113.10, and the internal IP is 192.168.1.10. The network administrator notices that the router's port forwarding rule is set to forward port 80 to 192.168.1.10:8080. What is the likely cause of the slow performance?

Accepted Answer

The port forwarding rule uses the wrong internal port. Port forwarding should map external port 80 to the server's internal port 80, not 8080 unless the server listens on 8080. If the server listens on port 80, the mismatch causes connection delays or errors as the router forwards to a closed port. Correcting the internal port resolves the issue.

Answer

The DNS server is misconfigured

Answer

The NAT table is full

Answer

The DHCP scope is exhausted

Question 7

A user reports that they can access internal resources using IP addresses but cannot access them using hostnames. Other users on the same network have no issues. What is the most likely cause?

Accepted Answer

The user's DNS settings are incorrect. The ability to use IP addresses but not hostnames points to a DNS resolution problem on the user's device. This could be due to a misconfigured DNS server address in the network settings or a local hosts file issue. Other users working normally suggests the problem is client-specific.

Answer

The DHCP server is out of addresses

Answer

The DNS server is down

Answer

The router's NAT is misconfigured

Question 8

A network administrator wants to ensure that all devices on a subnet automatically receive IP addresses from a specific range, and that the lease time is set to 8 hours. Which configuration file or service should be modified?

Accepted Answer

DHCP scope. The DHCP scope defines the range of IP addresses that a DHCP server can assign to clients on a subnet, along with lease duration and other options. By modifying the DHCP scope, the administrator can set the specific IP address range and configure the lease time to 8 hours, ensuring all devices on that subnet automatically receive addresses from that pool.

Answer

DNS zone file

Answer

NAT rules

Answer

QoS policy

Question 9

A user reports that their computer's clock is consistently off by several minutes, causing authentication failures with the domain. The network uses Active Directory. Which service should be checked first?

Accepted Answer

NTP. NTP (Network Time Protocol) is the correct service to check first because the symptom—a clock consistently off by several minutes causing authentication failures with an Active Directory domain—is a classic sign of time synchronization issues. Active Directory uses Kerberos for authentication, which requires the client and domain controller clocks to be within a default skew of 5 minutes (RFC 4120). If the time is off, Kerberos tickets are rejected, leading to authentication failures.

Answer

DHCP

Answer

DNS

Answer

RADIUS

Question 10

A company's internal website is accessible by IP address but not by its hostname. The website is hosted on a server with a static IP. Which service is most likely misconfigured?

Accepted Answer

DNS. This question tests DNS resolution for internal resources. Access by IP works, so the server is reachable. The problem is name resolution, which points to a missing or incorrect DNS record for that hostname.

Answer

DHCP

Answer

NAT

Answer

RADIUS

Question 11

A technician is setting up a new office network with 50 devices. The network must support growth up to 100 devices. The technician chooses a subnet mask of 255.255.255.0. How many usable host addresses does this subnet provide?

Accepted Answer

254. A subnet mask of 255.255.255.0 (or /24) provides 256 total addresses, with 254 usable for hosts (the first address is the network ID and the last is the broadcast address). This is sufficient for the current 50 devices and allows for growth up to 100, but not beyond 254.

Answer

255

Answer

256

Answer

128

Question 12

A user wants to connect a new laptop to a wired network that uses 802.1X authentication. What must be configured on the laptop to ensure successful network access?

Accepted Answer

Valid 802.1X credentials (username and password or certificate). This question tests knowledge of network authentication methods. 802.1X requires a username and password (or certificate) to authenticate to the network, typically via RADIUS. Without proper credentials, the switch port will remain blocked.

Answer

A static IP address in the same subnet as the network

Answer

The correct SSID and wireless security key

Answer

A crossover cable to connect to the switch

Question 13

A company deploys a new VoIP system. Users report that calls drop frequently. The network uses a single flat subnet with no QoS configured. The technician monitors traffic and sees high bandwidth utilization during peak hours. What is the most effective solution to improve call quality?

Accepted Answer

Replace all switches with managed switches and enable QoS. This question tests knowledge of Quality of Service (QoS) and network segmentation. VoIP traffic is sensitive to latency and jitter. Implementing QoS prioritizes voice traffic over other data, ensuring call quality even during high utilization. VLANs can also help by separating voice and data traffic.

Answer

Increase the bandwidth of the internet connection

Answer

Change all VoIP phones to use static IP addresses

Answer

Disable DHCP on the network to reduce broadcast traffic

Question 14

A company's web server is accessible from the internal network but not from the internet. The server has a static IP of 192.168.1.10. The firewall is configured to allow HTTP and HTTPS traffic. What is the most likely missing configuration?

Accepted Answer

Port forwarding rules are not configured on the firewall. The server has a private IP (192.168.1.10), so for internet clients to reach it, the firewall must translate the public destination IP to the private server IP using port forwarding (a form of Destination NAT). Without port forwarding rules, the firewall will receive HTTP/HTTPS traffic on its public interface but not know which internal server to send it to, even though the firewall's ACL allows the traffic. Option C correctly identifies this missing configuration.

Answer

The server's default gateway is set to the firewall's LAN IP

Answer

The firewall's NAT is disabled

Answer

The server has a public IP address assigned

Question 15

A technician is troubleshooting a network where users on one floor cannot access a server on another floor. Both floors are connected via a single fiber optic link. The technician checks the link and sees the switch port shows 'err-disabled' status. What is the most likely cause of this state?

Accepted Answer

Port security has been violated. The 'err-disabled' state on a switch port is commonly triggered by a port security violation. When a device attempts to connect with a MAC address that exceeds the configured maximum or is not on the allowed list, the switch disables the port to prevent unauthorized access. This matches the scenario where users on one floor cannot reach a server, as the link is physically intact but logically blocked.

Answer

The fiber cable is damaged

Answer

A duplex mismatch exists between the switches

Answer

The VLAN configuration is incorrect

Question 16

A company's IT policy requires that all network traffic from the guest Wi-Fi be isolated from the internal corporate network. The guest network uses a separate SSID and VLAN. Which additional configuration is necessary to ensure complete isolation?

Accepted Answer

Implement an ACL that denies traffic from the guest VLAN to the corporate VLAN. Access Control Lists (ACLs) on the router or firewall can block traffic between VLANs. Even with separate VLANs, inter-VLAN routing must be explicitly denied to prevent guest devices from reaching the corporate network.

Answer

Enable DHCP snooping on the guest VLAN

Answer

Configure a router-on-a-stick with subinterfaces

Answer

Set the guest network to use a different subnet mask

Question 17

A small office with 15 employees uses a single switch to connect all workstations. Users report that the network becomes extremely slow during peak hours, and some packets are being dropped. The switch is a 10/100 model with a 1 Gbps uplink to the router. What is the most likely cause of the slowdown?

Accepted Answer

The switch's ports are only 100 Mbps, causing a bottleneck when multiple users are active.. The switch operates at 10/100 Mbps per port, meaning each workstation is limited to a maximum of 100 Mbps. With 15 employees active during peak hours, the aggregate traffic can easily exceed the 100 Mbps per-port capacity, causing congestion, packet drops, and slowdowns. The 1 Gbps uplink to the router is not the bottleneck; the bottleneck is the 100 Mbps access ports connecting the workstations.

Answer

The switch is not a managed switch and cannot prioritize traffic.

Answer

The router's uplink port is faulty and needs to be replaced.

Answer

The switch is a hub, not a switch, causing collisions.

Question 18

A company is setting up a new branch office with 50 workstations and needs to connect them to the existing corporate network across a city. The connection must be dedicated and provide consistent bandwidth. Which type of WAN hardware should be installed at the branch office?

Accepted Answer

A CSU/DSU. This question tests knowledge of WAN hardware for dedicated connections. A CSU/DSU is used for T1 or leased lines, which provide dedicated bandwidth. Other options are for different connection types.

Answer

A DSL modem

Answer

A cable modem

Answer

A wireless access point

Question 19

A small business has a single router with four built-in switch ports. They need to connect 12 wired devices. They have a 24-port unmanaged switch. Which configuration will provide the best network performance and connectivity?

Accepted Answer

Connect the switch to one of the router's LAN ports, then connect all 12 devices to the switch.. Option B is correct because connecting the 24-port unmanaged switch to one of the router's LAN ports extends the network, allowing all 12 devices to connect via the switch. The router handles routing and DHCP, while the switch provides ample ports and wire-speed forwarding at Layer 2, ensuring optimal performance without collisions or bandwidth contention.

Answer

Connect all 12 devices directly to the router's four ports using splitters.

Answer

Connect half the devices to the router and half to the switch, then connect the switch to the router.

Answer

Use the router as a switch by disabling its routing functions.

Question 20

A user reports that their VoIP phone works but the connected PC cannot access the network. The phone is connected to the wall jack, and the PC is connected to the phone's passthrough port. What is the most likely cause?

Accepted Answer

The switch port is not configured for the data VLAN, so the PC cannot get an IP address.. The VoIP phone and PC share a single physical switch port via the phone's passthrough port. For the PC to access the network, the switch port must be configured as a trunk (or access port with voice VLAN) carrying both the voice VLAN (for the phone) and the data VLAN (for the PC). If the switch port is not configured for the data VLAN, the PC will not receive an IP address from the DHCP server and cannot communicate on the network, even though the phone works because it uses its own voice VLAN.

Answer

The PC's network cable is faulty.

Answer

The VoIP phone's passthrough port is disabled.

Answer

The PC's network adapter is set to a static IP address that conflicts with the phone.