Sample Questions from Cisco Certified Network Associate (CCNA)

Preview a few questions below — answers are revealed when you take the exam.

1. A network administrator is tasked with optimizing the performance of a Cisco switch in a high-traffic environment. The switch is experiencing congestion and packet loss. Which configuration change should the administrator implement to improve the switch's performance and reduce congestion?

   • Implement Quality of Service (QoS) policies to prioritize critical traffic and reduce congestion.
   • Increase the switch's buffer size to accommodate more packets and reduce the likelihood of packet loss.
   • Enable port aggregation to combine multiple physical ports into a single logical link, increasing bandwidth and reducing congestion.
   • Configure the switch to use a different spanning tree protocol, such as Rapid Spanning Tree Protocol (RSTP), to reduce convergence time and improve network stability.

2. A network engineer is designing a new VLAN configuration for a Cisco switch. The engineer wants to ensure that broadcast traffic is contained within each VLAN and does not propagate to other VLANs. Which configuration should the engineer implement to achieve this goal?

   • Configure each VLAN as a separate broadcast domain by assigning a unique VLAN ID to each VLAN and ensuring that inter-VLAN routing is properly configured.
   • Enable trunking on all switch ports to allow VLAN traffic to traverse the network and be routed between VLANs.
   • Configure each VLAN as a separate collision domain by assigning a unique MAC address to each VLAN and ensuring that MAC address filtering is enabled.
   • Disable spanning tree protocol (STP) on all switch ports to prevent broadcast storms and ensure that broadcast traffic is contained within each VLAN.

3. A network administrator is configuring a Cisco router to support multiple VLANs. The administrator wants to ensure that traffic between VLANs is routed efficiently and securely. Which configuration should the administrator implement to achieve this goal?

   • Configure inter-VLAN routing using a Layer 3 switch or a router with a VLAN interface for each VLAN, and implement access control lists (ACLs) to filter traffic between VLANs.
   • Configure a trunk link between the router and the switch to allow VLAN traffic to traverse the network, and implement VLAN tagging to identify VLAN traffic.
   • Configure a default gateway for each VLAN and ensure that the router is configured to forward traffic between VLANs.
   • Configure a static route for each VLAN and ensure that the router is configured to forward traffic between VLANs.

4. A network engineer is troubleshooting a connectivity issue between two Cisco switches. The engineer notices that the switches are not forming a trunk link, and VLAN traffic is not being transmitted between the switches. Which configuration should the engineer implement to resolve the issue?

   • Configure both switches to use the same trunk encapsulation protocol (e.g., IEEE 802.1Q or ISL) and ensure that the trunk link is enabled on both switches.
   • Configure both switches to use the same VLAN ID for the trunk link and ensure that the trunk link is enabled on both switches.
   • Configure both switches to use the same spanning tree protocol (e.g., STP or RSTP) and ensure that the trunk link is enabled on both switches.
   • Configure both switches to use the same IP address for the trunk link and ensure that the trunk link is enabled on both switches.

5. Identify the command used to display the current configuration of a Cisco switch.

   • show running-config
   • show startup-config
   • show version
   • show interfaces