- 2070 Chaitra · 8 marks
Repeater, hub, bridge, switch, router
Short answer
Repeater regenerates signals (Layer 1). Hub is a multiport repeater that broadcasts bits. Bridge and Switch operate at Layer 2, learning MAC addresses to forward frames selectively; Switch provides per-port collision domains. Router routes packets at Layer 3 using IP and routing tables.
Explain the working principle of the different types of network devices: Repeater, HUB, Bridge, Switch and Router.
| Device | Layer | Works on |
|---|---|---|
| Repeater, Hub | Physical (1) | Bits / signals |
| Bridge, Switch | Data link (2) | Frames, MAC address |
| Router | Network (3) | Packets, IP address |
Repeater
A repeater regenerates and amplifies a weak signal so that it can travel farther than the cable's maximum length (for example, 100 m for UTP). It connects two segments of the same LAN, does not filter traffic and does not know addresses. It cleans up the signal, so noise is not carried over.
Hub
A hub is a multiport repeater (physical layer). A frame received on one port is broadcast to all other ports. All devices share the same collision domain and bandwidth, so performance falls as devices are added. Half duplex only.
Bridge
A bridge connects two LAN segments at the data link layer. It reads the source MAC address of each frame to build a forwarding table (learning) and forwards a frame only to the segment holding the destination MAC (filtering). Unknown or broadcast frames are flooded. It divides the collision domain into smaller ones, but not the broadcast domain.
Switch
A switch is a multiport bridge implemented in hardware. Each port is its own collision domain and gets dedicated bandwidth. It learns MAC addresses, keeps a MAC table and forwards a unicast frame only to the correct port. Supports full duplex, VLANs and microsegmentation. A layer-3 switch can route.
Router
A router connects different networks at the network layer. It reads the destination IP address and consults a routing table (built by RIP, OSPF, BGP) to select the best next hop. It separates broadcast domains, can perform NAT and fragmentation, and can filter traffic with access lists. It is used to connect a LAN to the Internet.
PC--[Switch]--[Router]--Internet
PC--[Hub]----/
✓ Answer checked by Claude Opus 5.5 (high effort)
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