Repeaters vs hubs vs bridges vs switches
Hubs vs. Switches: Key Differences
Hubs and switches are both networking devices that connect multiple devices in a LAN, but they operate very differently at the data link layer (Layer 2) of the OSI model.
Key Technical Differences
Operation
Operates at Layer 1 (Physical)
Operates at Layer 2 (Data Link)
Traffic Handling
Broadcasts all incoming data to all ports (flooding)
Forwards traffic only to the destination port using MAC addresses
Collision Domain
Single collision domain (all devices share bandwidth)
Per-port collision domain (isolates traffic, full-duplex possible)
Bandwidth Usage
Shared bandwidth (e.g., 10Mbps hub divides bandwidth among all ports)
Dedicated bandwidth per port (e.g., 100Mbps per port)
Performance
Slower (due to collisions and unnecessary traffic)
Faster (efficient forwarding, no unnecessary broadcasts)
MAC Address Learning
No (does not track devices)
Yes (maintains a MAC address table for forwarding decisions)
Security
Less secure (all devices see all traffic)
More secure (isolates traffic between ports)
Use Case
Obsolete (used in early networks)
Modern standard (used in all current networks)
What Can Switches Do That Hubs Cannot?
MAC Address Learning & Forwarding – Switches maintain a MAC address table to send frames only to the correct port, while hubs blindly broadcast.
Full-Duplex Communication – Switches allow simultaneous two-way communication (send & receive at the same time), whereas hubs operate in half-duplex (collisions occur).
Collision Avoidance – Switches eliminate collisions via per-port segmentation, unlike hubs, which suffer from CSMA/CD (Carrier Sense Multiple Access with Collision Detection).
VLAN Support – Switches can segment networks into VLANs (Virtual LANs), while hubs cannot.
Traffic Optimization – Switches reduce unnecessary traffic, improving efficiency, whereas hubs waste bandwidth.
Conclusion
Switches are vastly superior to hubs in speed, efficiency, and security. Hubs are obsolete in modern networks due to their broadcast nature and shared bandwidth limitations.
Hubs vs. Bridges vs. Switches: Key Differences
Here’s an expanded comparison table that includes bridges, which sit between hubs and switches in terms of functionality.
Feature
Hub (Layer 1)
Bridge (Layer 2)
Switch (Layer 2, Advanced)
OSI Layer
Physical (Layer 1)
Data Link (Layer 2)
Data Link (Layer 2)
Traffic Handling
Broadcasts to all ports (flooding)
Forwards based on MAC addresses (filtering)
Forwards based on MAC table, per-port forwarding
Collision Domain
Single collision domain (all ports share bandwidth)
Divides collision domains (2 or more segments)
Per-port collision domain (full-duplex possible)
Bandwidth Usage
Shared (e.g., 10Mbps divided among all ports)
Semi-dedicated (reduces unnecessary traffic)
Dedicated per port (e.g., 100Mbps per port)
MAC Learning
No (dumb device)
Yes (maintains a simple MAC table)
Yes (maintains a full MAC table for all ports)
Ports
Typically 4–12 ports
Usually 2 ports (connects two network segments)
4–48+ ports (scalable)
Performance
Slow (collisions, broadcasts)
Moderate (reduces collisions but limited ports)
Fast (no collisions, optimized forwarding)
Security
None (all traffic visible to all devices)
Basic filtering (isolates segments)
Better isolation (per-port forwarding, VLAN support)
Use Case
Obsolete (historical use)
Legacy segmentation (older networks)
Modern standard (all Ethernet networks)
Key Takeaways:
Hubs = Dumb repeaters (no intelligence, all traffic broadcasted).
Bridges = Basic traffic filters (split collision domains, simple MAC learning).
Switches = Advanced bridges (full MAC tables, dedicated bandwidth, VLANs, high port density).
Bridges were an early improvement over hubs but were later replaced by switches, which offer more ports, faster forwarding, and better scalability.
Repeaters vs. Hubs vs. Bridges vs. Switches: Key Differences
Feature
Repeater (L1)
Hub (L1)
Bridge (L2)
Switch (L2, Advanced)
OSI Layer
Physical (L1)
Physical (L1)
Data Link (L2)
Data Link (L2)
Function
Regenerates signals (extends cable reach)
Multi-port repeater (broadcasts to all ports)
Connects two network segments (filters by MAC)
Multi-port bridge (intelligent forwarding)
Traffic Handling
No filtering (boosts signal only)
Broadcasts to all ports (no intelligence)
Forwards based on MAC table (2 ports only)
Forwards based on full MAC table (per-port)
Collision Domain
Extends collision domain (no isolation)
Single collision domain (all ports share bandwidth)
Splits collision domains (two segments)
Per-port collision domain (full-duplex possible)
Bandwidth Usage
No improvement (just extends signal)
Shared (e.g., 10Mbps divided among all ports)
Reduces unnecessary traffic (basic filtering)
Dedicated per port (e.g., 100Mbps per port)
MAC Learning
No (dumb signal booster)
No (dumb device)
Yes (basic MAC table for two ports)
Yes (full MAC table for all ports)
Ports
2 ports (in/out)
4–12 ports (multi-port repeater)
2 ports (links two hubs/segments)
4–48+ ports (scalable)
Performance
No speed improvement (just extends range)
Slow (collisions, broadcasts)
Moderate (reduces collisions but limited ports)
Fast (no collisions, optimized forwarding)
Security
None (raw signal passthrough)
None (all traffic visible to all devices)
Basic filtering (isolates segments)
Better isolation (per-port forwarding, VLAN support)
Use Case
Extending cable runs (e.g., Ethernet, fiber)
Obsolete (historical use)
Legacy segmentation (older networks)
Modern standard (all Ethernet networks)
Key Takeaways
Repeaters extend signals but do nothing for traffic efficiency.
Hubs are just multi-port repeaters—they flood all traffic, creating congestion.
Bridges improve on hubs by splitting collision domains but are limited to 2 ports.
Switches are scalable, high-performance bridges with per-port forwarding.
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