Cisco CCNA Practice Test (200-301)

Switches that operate at the data link layer (Layer 2) cannot route traffic between different IP networks because they do not process or understand IP addresses. They forward frames based on MAC addresses within the same network segment. Routing between different IP networks requires network layer (Layer 3) functionality, which is provided by routers or Layer 3 switches that can interpret IP addresses and make routing decisions accordingly.

To configure a default route in IPv4 on a Cisco router, you use the command ip route 0.0.0.0 0.0.0.0 192.168.1.1. The 0.0.0.0 0.0.0.0 specifies a destination network of all zeros with a subnet mask of all zeros, which matches any IPv4 address not found in the routing table. This tells the router to forward packets destined for unknown networks to the next-hop IP address 192.168.1.1. The other options are incorrect because:

• ip route 0.0.0.0 255.255.255.255 192.168.1.1 defines a route to a specific host address 0.0.0.0, not a default route.
• ip default-gateway 192.168.1.1 is used on devices without IP routing enabled, such as switches, and is not appropriate when IP routing is active.
• ip route any any 192.168.1.1 is not a valid Cisco IOS command for configuring routes.

This statement is false. Dynamic ARP Inspection (DAI) depends on the DHCP snooping binding table to validate ARP packets. DAI uses the IP-to-MAC address mappings collected by DHCP snooping to ensure that incoming ARP packets are from legitimate sources. Without the DHCP snooping binding table, DAI cannot perform this validation, leaving the network vulnerable to ARP spoofing attacks.

JSON formatting makes the configuration data easy to parse and use in automation scripts.

The service password-encryption command encrypts all plaintext passwords in the configuration file using a Cisco proprietary encryption algorithm. This helps in protecting the passwords from being easily read if someone views the configuration file. The enable secret command sets an encrypted password for privileged access but does not encrypt other plaintext passwords in the configuration. The username admin secret cisco command creates an encrypted password for a specific user but doesn't affect existing plaintext passwords. The password encryption aes command is not a valid Cisco IOS command for encrypting passwords.

In OSPF broadcast networks, the primary factor for electing the Designated Router (DR) is the interface priority value assigned to each router. The router with the highest interface priority becomes the DR. If multiple routers have the same highest priority, the router with the highest Router ID is selected. Interface priority is configurable and allows network administrators to influence DR election, making it the most significant criterion in the selection process.

The password [password] command is used within line configuration mode to set the password required to access a specific line, such as the console line (line console 0). This command defines the password that users must enter when connecting to that line. The enable password [password] and enable secret [password] commands set passwords for privileged EXEC mode access, not for line access. The service password-encryption command encrypts passwords in the device's configuration but does not set any passwords.

Next-generation firewalls provide advanced security features such as user identity enforcement, intrusion prevention, and application-layer traffic inspection. These capabilities allow them to detect and block sophisticated threats while enforcing detailed security policies. Traditional stateful firewalls lack these advanced features and only perform basic packet filtering and state tracking. Layer 3 switches handle routing and basic access control lists but do not offer deep security functionalities. Intrusion Detection Systems can detect threats but cannot enforce policies or control traffic flow.

Cisco Digital Network Architecture Center (DNA Center) is specifically designed to offer automation, policy enforcement, and detailed analytics across wired and wireless infrastructures. It serves as a centralized network controller that simplifies management tasks, ensures consistent security policies, and provides network assurance through analytics. While a Wireless LAN Controller manages wireless access points, it doesn't automate wired network provisioning or deliver extensive analytics. Cisco Prime Infrastructure offers network management but lacks the advanced automation and policy capabilities of DNA Center. Cisco Firepower Management Center focuses on security appliance management rather than holistic network automation and policy enforcement.

A router operates at Layer 3 of the OSI model and uses IP addresses to forward data packets between different networks. It determines the best path for the data to reach its destination across interconnected networks. A switch operates at Layer 2 and uses MAC addresses to forward data within the same network. A hub simply broadcasts data to all its ports without any form of intelligent packet directing, and a repeater amplifies signals but does not make forwarding decisions based on addresses.

On Cisco switches, the default VLAN is VLAN 1, which is assigned by default to all switch ports and cannot be deleted. This default network segment carries control traffic such as CDP and STP. The correct answer is that it is assigned by default to all ports and cannot be deleted. Option B is incorrect because voice traffic is typically assigned to a separate voice VLAN, not the default VLAN. Option C is incorrect because, while it's a security best practice to avoid using the default VLAN for user data traffic, the default VLAN itself cannot be removed from the switch. Option D is incorrect because the default VLAN is not specifically used for management traffic and can be used for other user traffic; management functions can be configured on different VLANs.

The switchport mode vlan associates a port with a particular VLAN, segregating traffic and improving network organization.

To minimize interference between access points, non-overlapping channels should be used for adjacent access points. This practice reduces co-channel interference and ensures better wireless performance. Configuring each access point to operate on the same channel can cause overlapping signals and increase interference. Setting the transmit power of each access point to the maximum level may extend coverage but can also amplify interference in overlapping areas. Disabling the Service Set Identifier (SSID) broadcast does not affect interference levels but makes the network less visible to users.

WPA3 provides the strongest level of security among the listed wireless security protocols. It introduces advanced encryption and authentication methods that offer better protection against modern threats. WEP and WPA have significant vulnerabilities and are considered insecure. While WPA2 is still commonly used and provides strong security, WPA3 includes enhancements that address weaknesses in WPA2 and offers improved safeguards against attacks such as offline dictionary attacks.

Layer 3 switches can perform routing by forwarding packets based on IP addresses, enabling communication between different subnets. This is a function that Layer 2 switches cannot perform, as they only forward frames based on MAC addresses within the same subnet. Filtering frames based on MAC addresses is a function shared by both Layer 2 and Layer 3 switches. Providing Power over Ethernet (PoE) is related to supplying power over network cables and is not exclusive to either layer. Converting optical signals to electrical signals is the role of media converters, not switches.