For a campus network with about 800 hosts and 10 VLANs, the choice between a router and a Layer 3 switch depends on several factors, including network structure, performance requirements, security, traffic management, and costs.

Below are key considerations in making this decision:

Layer 3 Switch

Layer 3 switches combine the functionality of traditional Layer 2 switches with some of the routing capabilities of routers. They are ideal for large networks due to their ability to manage multiple VLANs and perform routing between them, all at speeds very close to hardware.

Advantages:

• High Performance and Low Latency: Ideal for handling internal traffic within the campus network, especially for latency-sensitive applications.
• Scalability: Facilitates the management of multiple VLANs and network expansion.
• Network Simplification: Reduces the need for multiple physical devices by consolidating routing and switching functionality into a single device.

Considerations:

• Although Layer 3 switches are efficient for inter-VLAN routing and handling internal traffic, they may not have all the advanced security features, routing policies, and support for WAN protocols that dedicated routers offer.

Router

Routers are devices that are primarily used to connect multiple networks and direct traffic between them. In the context of a campus network, a router would be useful to manage traffic between the campus network and other external networks, such as the Internet.

Advantages:

• Advanced Features: They offer advanced security capabilities, QoS (Quality of Service), VPN, and support for multiple routing protocols.
• Connection with External Networks: They are ideal for managing WAN connections and the interface with the Internet.

Considerations:

• They generally have lower performance and higher latency in internal routing compared to Layer 3 switches, especially in networks with high volumes of internal traffic.

Conclusion

For a campus network with 800 hosts and 10 VLANs:

• Layer 3 Switch would be more suitable for managing internal network traffic. Its ability to perform high-speed routing between VLANs and deliver performance close to that of Layer 2 switching makes it ideal for supporting the density and traffic demands of a campus network.
• Router would be needed to manage traffic between the campus network and external networks, providing advanced security and routing protocols.

In many modern network architectures, a combination of both is used: Layer 3 switches for internal routing and VLAN management, and routers for external connection and implementing advanced security policies.

This provides a balance between performance, security and management flexibility.