Hub vs Switch vs Router — Key Differences Explained

A hub broadcasts every frame to all connected ports (Layer 1, no intelligence). A switch forwards frames only to the correct port using MAC addresses (Layer 2). A router routes packets between different networks using IP addresses (Layer 3). Hubs are obsolete — modern networks use switches and routers.

Key takeaways

Hub = Layer 1 — no intelligence, broadcasts to all ports, creates one collision domain, completely obsolete
Switch = Layer 2 — uses MAC address table, one collision domain per port, full-duplex, widely used in LANs
Router = Layer 3 — uses IP routing table, separates broadcast domains, connects different networks
Home routers are 3-in-1 devices: router + switch (LAN ports) + wireless access point
Layer 3 switches can route between VLANs without a separate router — used at distribution/core layer
Switches flood unknown unicast frames to all ports — this is not a security risk in normal operation
Default gateway = the router's IP address that devices send traffic to when destination is outside local network

Quick answer: A hub broadcasts every frame to all connected devices (Layer 1). A switch forwards frames only to the correct device using MAC addresses (Layer 2). A router forwards packets between different networks using IP addresses (Layer 3). Hubs are obsolete, switches and routers do all the work in modern networks.

Quick Comparison Table

Feature	Hub	Switch	Router
OSI Layer	Layer 1 (Physical)	Layer 2 (Data Link)	Layer 3 (Network)
Addressing	None	MAC address	IP address
Forwarding	Broadcast to all ports	Unicast to specific port	Routes between networks
Collision domain	One (shared)	One per port	One per port
Broadcast domain	One	One per VLAN	One per interface, stops broadcasts
Intelligence	None	MAC address table	Routing table
Typical port count	4 to 24	8 to 48+	Few (2 to 8)
Duplex	Half-duplex only	Full-duplex	Full-duplex
Used today?	Obsolete	Every LAN	Between networks, internet edge

What is a Hub?

A hub is the simplest network device, it has no intelligence at all. Every frame received on any port is immediately retransmitted out every other port. It operates at OSI Layer 1 and has no awareness of MAC or IP addresses.

Collisions: all ports share one collision domain, so only one device can transmit at a time
Security risk: every device sees every frame, trivial to capture traffic with a packet analyser
Wasted bandwidth: a 100 Mbps hub shared among eight devices averages about 12.5 Mbps each

Hubs have not been manufactured for mainstream use since the early 2000s. If you find one in a rack, replacing it with a switch is almost always an instant performance win.

What is a Switch?

A network switch is an intelligent Layer 2 device. When a frame arrives, the switch reads the source MAC address and records which port it came from in its MAC address table (also called the CAM table). When forwarding, it sends the frame only to the port where the destination MAC lives, not to every port like a hub.

How a switch forwards a frame

A frame arrives on port 1 from Device A (MAC AA:AA:AA:AA:AA:AA)
The switch records: port 1 = AA:AA:AA:AA:AA:AA
It reads the destination MAC BB:BB:BB:BB:BB:BB
If that MAC is in the table on port 3, the frame goes only to port 3
If it is not in the table, the frame is flooded to all ports, an unknown unicast flood

Types of switch

Unmanaged: plug and play, no configuration, home and small office
Managed: VLANs, spanning tree, port security, monitoring, enterprise
Layer 3 switch: routes between VLANs without a separate router
PoE switch: powers IP phones, cameras and access points over the Ethernet cable

What is a Router?

A router operates at Layer 3 and connects different networks together. A switch works with MAC addresses inside one network; a router works with IP addresses and decides which network to send a packet toward next.

Your home router connects your local network (192.168.x.x) to your ISP’s network and onward to the internet. Without it your devices could talk to each other but nothing beyond.

What a router does with a packet

Reads the destination IP address
Looks it up in the routing table and picks the best match
Decrements the TTL, dropping the packet if it reaches zero
Strips the old Layer 2 header and writes a new one for the next hop
Forwards it out the chosen interface

Router features

NAT: translates private addresses to one public address
DHCP server: hands out IP addresses to connected devices
Firewall: packet filtering, stateful on most modern routers
Routing protocols: BGP, OSPF and EIGRP to learn routes dynamically
QoS: prioritises traffic, important for voice and video

Router vs Switch, the Direct Comparison

This is the pairing people actually compare, since hubs are gone. The difference comes down to which OSI layer the device works at, and that single fact explains everything else.

Parameter	Switch	Router
Operates at	Layer 2 (Data Link)	Layer 3 (Network)
Decides using	MAC address	IP address / subnet
Connects	Devices within one network	Separate networks to each other
Lookup table	MAC address table, learned automatically	Routing table, static or learned by protocol
Broadcasts	Forwards them within the VLAN	Blocks them, each interface is its own broadcast domain
Port count	High, 8 to 48 and beyond	Low, usually a WAN port and a few LAN ports
Port types	LAN ports of the same type	WAN and LAN, often different media
Forwarding speed	Faster, done in hardware ASICs	Slower per packet, more processing per hop
Segmentation	VLANs	Subnets and VRFs
Cost per port	Lower	Higher

Three things people get wrong

“A router has more ports than a switch.” The opposite. A router typically has a handful of interfaces; switches are built for port density.
“Switches cannot control traffic.” Managed switches do QoS, storm control, port security, rate limiting and ACLs. Traffic control is not exclusive to routers.
“A router is more secure than a switch.” Neither is inherently more secure. They enforce different controls at different layers, a router filters between networks, a switch controls what can attach to a port and which VLAN it lands in.

When to Use Each Device

Use case	Device
Connect PCs on the same floor or office	Switch
Connect the office to the internet	Router
Connect two separate sites	Router plus a WAN link
Split an office into departments	Managed switch with VLANs
Route between VLANs without a separate router	Layer 3 switch
Power IP phones, cameras or access points	PoE switch
Home network	Home router, router, switch and access point in one box

Your Home Router Is All Three in One Box

What people call a home “router” is really three devices sharing an enclosure: a router between your LAN and the internet, a switch providing the LAN ports on the back, and a wireless access point providing the Wi-Fi. Enterprise networks split these into separate dedicated devices for performance, redundancy and manageability.

Frequently Asked Questions

What is the main difference between a router and a switch?

A switch forwards frames within a single network using MAC addresses at Layer 2. A router forwards packets between different networks using IP addresses at Layer 3. Everything else, port count, cost, speed, how broadcasts are handled, follows from that.

Can a switch replace a router?

A Layer 2 switch cannot, it has no way to route between IP networks. A Layer 3 switch can route between VLANs inside your organisation, but you still need a router or firewall to reach the internet.

Does a router have more ports than a switch?

No, fewer. Routers usually have a small number of interfaces, often one WAN and a few LAN. Switches are designed for port density and commonly have 24 or 48.

Does a router have a MAC address?

Yes. Every router interface has both a MAC address for Layer 2 communication and an IP address for Layer 3 routing. When your PC sends traffic to its default gateway, it addresses the frame to the router’s MAC.

What is the default gateway?

The router IP address that devices send traffic to when the destination is outside their own network. If your PC is 192.168.1.10 and the router is 192.168.1.1, then 192.168.1.1 is the default gateway.

Is a firewall a router?

A firewall can route, but its purpose is filtering and security enforcement. A router’s purpose is path selection and forwarding. In enterprise networks the firewall usually sits between the router and the internal network.

Why are hubs obsolete?

A hub puts every device in one collision domain and lets every device see every frame, bad for both performance and security. Switches solved both problems and cost no more, so hubs disappeared.

Related Guides

Read network devices explained, what a network switch is, what a router is and which OSI layer a router operates at. For segmentation see what a VLAN is and collision and broadcast domains, or start with the OSI model complete guide. Shopping for hardware? See our best PoE switches guide.

Written by

Gurpreet Singh

Hey! I"m Gurpreet Singh and I Have 7+ Years of experience in the Network & Security Domain as well as the Cloud Infra Domain. I am Certified with Cisco ( CCNA ), CheckPoint ( CCSA ), 1xAWS, 3xAZURE, and 3xNSE. So I love to share my tech knowledge with you.