You want to improve network performance by increasing the bandwidth available to hosts and at the same time limit the size of broadcast domains for better scalability and security. Which option provides both higher bandwidth and smaller broadcast domains in a switched network?

Introduction / Context:
Modern enterprise networks must balance the need for higher bandwidth with the need to control broadcast traffic and isolate groups of users for security. Simple shared media such as hubs cannot provide sufficient bandwidth or isolation. Switches introduce microsegmentation by providing dedicated bandwidth per port, and VLANs allow logical segmentation that breaks large broadcast domains into smaller ones. This question asks you to choose the option that simultaneously increases bandwidth for hosts and reduces broadcast domain size.

Given Data / Assumptions:

• The network currently experiences broadcast traffic that affects many hosts.
• There is a requirement to give hosts more bandwidth than a shared hub would provide.
• Segmentation of users into smaller groups is desired for performance and security.
• Cisco style switches are available so that VLANs can be configured.

Concept / Approach:
Switches operate at layer 2 and provide dedicated collision domains for each port, which effectively gives each host its own segment and improves bandwidth compared to hubs. However, if all ports are in a single VLAN, they still share one broadcast domain. By configuring multiple VLANs on the switches and assigning ports appropriately, you create multiple smaller broadcast domains. Each VLAN is its own logical network, and broadcasts stay within that VLAN. This approach delivers both improved per host bandwidth and reduced broadcast domain size. Other devices like hubs and unmanaged repeaters simply repeat signals and do not provide segmentation or additional bandwidth beyond the shared medium.

Step-by-Step Solution:
1. Recognize that hubs and repeaters operate at the physical layer and create a single shared collision domain, so they do not increase per host bandwidth or limit broadcast domains. 2. Understand that basic switches already provide separate collision domains per port, increasing bandwidth compared to hubs. 3. However, if the switch uses only one VLAN, all ports are still in a single broadcast domain. 4. Introducing multiple VLANs on the switches breaks the network into several logical segments, each with its own broadcast domain. 5. Hosts within each VLAN enjoy dedicated switch port bandwidth and are not impacted by broadcast traffic from other VLANs. 6. Conclude that switches configured with multiple VLANs best satisfy both requirements.

Verification / Alternative check:
Consider a scenario with one switch and 48 hosts. With a single VLAN, a broadcast from any host is seen by all 47 others. If you create four VLANs of 12 hosts each, a broadcast in one VLAN is seen by only 11 other hosts, greatly reducing broadcast scope. At the same time, each host still has a dedicated switch port, so there is no shared collision domain. This confirms that using switches with VLANs achieves higher bandwidth and smaller broadcast domains simultaneously.

Why Other Options Are Wrong:
Option a: Managed hubs may offer management features, but they still operate as multiport repeaters, sharing bandwidth among all ports and maintaining a single broadcast and collision domain. Option b: Bridges can segment collision domains between segments, but a single bridge does not provide the same flexible VLAN based segmentation and scalability as modern switches. Option c: Switches with a single VLAN improve collision domain separation but do not limit broadcast domains, since all ports still share one broadcast domain. Option e: Unmanaged repeaters simply regenerate electrical signals and offer no segmentation or bandwidth improvement per host.

Common Pitfalls:
A common misunderstanding is thinking that switches alone automatically solve broadcast traffic issues. While they solve collisions, they do not reduce broadcast domain size unless VLANs are used. Another pitfall is assuming that bridges and switches are equivalent for all scale levels. In large networks, VLAN capable switches provide far more flexibility and performance. Also, some learners confuse collision domains with broadcast domains; it is important to remember that VLANs define broadcast domains, while switch ports define collision domains.

Final Answer:
The best way to increase bandwidth and limit broadcast domain size is to use switches configured with multiple VLANs.