What Is a Network Hub? Uses, Risks, and Better Solutions

What Is a Network Hub?

A network hub is a hardware device used to connect multiple devices to a single network. The hub serves as a central point of connection, enabling communication between all connected devices.

A network hub operates at Layer 1 (the physical layer) of the OSI (Open Systems Interconnection) model; it broadcasts data packets to all of its connected devices, regardless of which device the data is intended for.

It has no awareness of MAC addresses, IP addresses, or any higher-layer protocol, so it cannot make forwarding decisions; it simply repeats the electrical signal out of every port.

Hubs were once a standard part of network infrastructure, used to connect multiple machines in a local area network (LAN). Today, they have largely been replaced by more sophisticated devices like network switches.

How Do Network Hubs Work?

When a data packet is sent to a hub, the hub broadcasts that packet to all ports and connected devices. Each connected device then determines whether the packet is intended for it. If a packet is intended for a specific device, that device processes it while all other devices discard it.

This process is fundamental to how hubs operate. However, it also introduces significant inefficiencies and security risks:

• Because every device receives every packet, network performance degrades as more devices are added to the hub.
• Any device on the segment can observe all traffic passing through it.

Two technical properties explain why this design scales so poorly:

1. Every device connected to a hub shares a single collision domain. When two devices transmit at the same time, their signals collide, both transmissions are corrupted, and every device must stop and retry after a random delay.
2. A hub can only operate in half-duplex mode, meaning a device can either send or receive at any given moment, never both at once. As more devices join the hub, collisions multiply and usable throughput drops sharply.

Common Types of Network Hubs

There are three primary types of network hubs that were commonly deployed: passive hubs, active hubs, and intelligent hubs. Each type serves different roles in a network, but all share the same fundamental broadcast behavior.

Passive Hubs

Passive hubs do not require any power to operate. They simply act as a conduit, connecting devices without amplifying or modifying the transmitted signals. Passive hubs are the most basic form of hub and are typically used in small, simple networks where signal degradation over distance is not a concern.

Their lack of power requirements makes passive hubs straightforward to deploy, but they provide no signal amplification, meaning cable runs are limited to shorter distances.

Active Hubs

Active hubs, unlike their passive counterparts, require power to operate. They amplify the electrical signal before passing it to connected devices. This process allows for longer cable runs and more reliable data transmission across a larger area.

This signal regeneration is the key distinguishing feature of active hubs. Active hubs are also known as multiport repeaters because they repeat and amplify incoming signals across all ports.

Intelligent Hubs

Intelligent hubs, also known as smart hubs, are the most advanced type of network hub. In addition to the amplification capabilities of active hubs, intelligent hubs come equipped with management software that allows network administrators to monitor network traffic, diagnose issues, and sometimes configure individual ports.

This management capability makes them more suitable for environments where some degree of visibility into network performance is required, though they still cannot match the traffic isolation and security features of a network switch.

Benefits of Network Hubs

Network hubs offer a small set of practical advantages, particularly in specific constrained use cases:

• Cost: Hubs are inexpensive hardware. For a small home lab, classroom, or test environment where security is not a concern, a hub’s low purchase price can make it an attractive choice when a switch is not available.
• Simplicity: Hubs require zero configuration. Plug in the cables, and devices are connected. There is no virtual LAN (VLAN) segmentation to configure, no access control lists to manage, and no firmware to update. For temporary setups or isolated test networks, this plug-and-play behavior eliminates setup overhead entirely.
• Built-in traffic visibility: Because a hub broadcasts all traffic to all ports, a network analyzer or packet capture tool connected to any port can observe the full traffic stream on that segment. This behavior, which is a liability in production environments, becomes a diagnostic advantage in a controlled lab. Engineers who need to capture traffic passively without reconfiguring a switch mirror port sometimes use a hub for this purpose.
• Legacy device compatibility: Some older devices communicate at speeds or with protocols that assume hub-based broadcast behavior. In rare legacy environments where upgrading those devices is not feasible, a hub may be the lowest-friction connection method.

Network Hub Security Vulnerabilities

Network hubs have several significant security vulnerabilities that make them unsuitable for most modern networks:

• Packet sniffing
• ARP flooding and broadcast storms
• Lack of port security
• Lack of encryption
• Inability to segment networks
• Network congestion
• Susceptibility to eavesdropping

Packet Sniffing

Because a hub broadcasts every packet to every connected port, any device attached to the hub can see all traffic on that network segment, not just traffic addressed to it.

A threat actor who gains physical access to any hub port, or who plants malware on a connected device, can run a packet capture tool and observe all usernames, passwords, session tokens, and unencrypted data flowing through the hub.

This is not a configuration flaw; it is the hub’s fundamental operating mode. Unlike a network switch, which forwards frames only to the intended destination port, a hub provides no mechanism to contain traffic within a port pair.

ARP Flooding and Broadcast Storms

Hubs retransmit every incoming packet to all ports, including broadcast frames. In larger hub-connected networks, broadcast traffic can multiply rapidly.

If a misconfigured device or a malicious actor begins sending high volumes of broadcast packets (a technique known as ARP flooding), the hub will faithfully retransmit each one to every port, consuming available bandwidth for all connected devices.

Because hubs have no mechanism to suppress or filter broadcasts, a single misbehaving device can degrade the entire segment. This condition is called a broadcast storm, where broadcast traffic cascades uncontrollably across the network, saturating bandwidth and potentially bringing communication to a halt.

Lack of Port Security

Hubs cannot enforce any form of port-level access control. Any device plugged into a hub port immediately becomes part of the network segment. There is no way to require 802.1X authentication before granting access, bind a port to a specific MAC address, or quarantine a device that fails a policy check.

This makes hubs incompatible with any compliance framework that requires network access control, including PCI-DSS, HIPAA, and frameworks that mandate zero-trust segmentation.

Lack of Encryption

Hubs do not provide any form of data encryption. All data transmitted through a hub is in plaintext, making it easily readable to anyone who can capture the traffic.

Inability to Segment Networks

Hubs cannot segment networks or create VLANs. All devices connected to a hub are on the same network segment, which makes it impossible to separate different types of traffic or create security boundaries between devices.

Network Congestion

Since all devices share the same bandwidth in a hub-based network, network congestion can easily occur. As the number of connected devices grows, the available bandwidth for each device decreases, leading to slow speeds and poor performance.

Susceptibility to Eavesdropping

Hubs make it easy for malicious actors to intercept data using packet sniffers. Since all data is broadcast to every device on the network, anyone with a packet sniffer and a connection to the hub can capture and read data that is not intended for them.

Network Hub Security Protocols vs. Modern Security Solutions

Given the security limitations of network hubs, modern network security has moved beyond hubs to solutions that provide robust controls at the network access layer.

Network Switches

Network switches offer a significant improvement over hubs in terms of both performance and security. Switches operate at Layer 2 of the OSI model and use MAC addresses to send data only to the intended recipient device, rather than broadcasting to all devices. This reduces unnecessary network traffic and makes eavesdropping significantly more difficult.

Advanced network switches incorporate security features including:

• Virtual Local Area Network (VLANs)

VLANS allow network administrators to segment a network into distinct zones, limiting the potential damage from a security incident

• Port Security

Port Security allows administrators to control which devices can connect to a network based on their MAC addresses.

• Access Control Lists (ACLs)

ACLs provide fine-grained control over which types of traffic are allowed or denied on the network.

RADIUS and EAP Solutions

Modern network security platforms go beyond what a switch alone can provide. Solutions that implement RADIUS-based network access control and Extensible Authentication Protocol (EAP) certificate authentication, using EAP-TLS, ensure that only verified, policy-compliant devices can join the network at all.

JoinNow Cloud RADIUS enables organizations to enforce certificate-based authentication at the point of network access, eliminating the credential-based risks that hub-era networks could never address. For organizations that need to manage the certificates that power that authentication, a cloud public key infrastructure (PKI) supplies the underlying trust; Dynamic PKI provides that certificate infrastructure.

Here’s a closer look at how Cloud RADIUS works:

Network Hub vs. Network Switch vs. Router

While both network hubs and switches are used to connect multiple devices in a LAN, they operate in fundamentally different ways, and those differences have direct security implications. A router adds a third tier to the comparison: it works at Layer 3 to connect separate networks rather than devices on one segment.

Feature	Network Hub	Network Switch	Router
OSI layer	Layer 1 (Physical)	Layer 2 (Data Link)	Layer 3 (Network)
Forwarding basis	None — broadcasts to all ports	MAC address	IP address
Traffic delivery	Broadcasts to all ports	Forwards to destination port only	Routes between networks
Connects	Devices on one segment	Devices on one segment	Separate networks (LANs, WANs)
VLAN support	No	Yes (managed switches)	Yes
Port security	No	Yes (managed switches)	N/A
802.1X support	No	Yes (managed switches)	N/A
Packet sniffing risk	High (all traffic visible to all ports)	Low (traffic isolated per port)	Low
Typical use today	Legacy/lab only	Universal LAN standard	Connecting networks

The most significant practical difference is traffic isolation. A switch maintains a MAC address table and forwards each frame only to the port associated with the destination MAC address. This means a device connected to port 3 cannot passively observe traffic flowing between devices on ports 1 and 2. A hub provides no such isolation; port 3 sees everything.

A Brief History of the Network Hub

Ethernet hubs became common in the early 1990s as a cheaper, more manageable alternative to the shared coaxial cabling of early Ethernet, giving each device its own port on a central device.

Through the late 1990s, the network switch emerged as a more capable replacement: by reading MAC addresses and forwarding frames only to the destination port, a switch eliminated the collisions and broadcast exposure that hubs could not avoid. As switch prices fell to near parity with hubs through the early-to-mid 2000s, hubs were phased out of mainstream networking, and most vendors stopped selling them in favor of low-cost unmanaged switches.

Are Network Hubs Ever Used Today?

While network hubs were once a common component of network infrastructure, they are rarely used in modern networks. Network switches, which offer superior performance, security, and scalability, have largely displaced hubs in production environments.

However, there are some scenarios where hubs may still be used. For example, in certain legacy environments, hubs may still be present due to the cost and complexity of upgrading to modern network equipment. Additionally, as noted above, hubs are sometimes used in network testing and troubleshooting environments, where their traffic broadcasting behavior can be advantageous for capturing all network traffic for analysis.

In general, if you have a choice between using a hub and a switch, a switch is almost always the better option. Switches provide better performance, security, and scalability, and the cost difference between the two devices has become negligible.

Secure Your Network With SecureW2

Network hubs illustrate the risks of infrastructure that cannot control who sees what. Modern network security begins with the ability to authenticate every device before it joins the network, segment traffic by policy, and revoke access instantly when a device falls out of compliance.

SecureW2 provides the cloud-native infrastructure to make that possible. The JoinNow Cloud RADIUS platform integrates with your existing switches and wireless access points to enforce certificate-based 802.1X authentication at the point of network access, so no device without a valid, policy-matched certificate can connect. Pair it with Dynamic PKI for automated certificate lifecycle management across your entire device fleet.

If your network still relies on shared credentials, legacy access methods, or hardware that cannot enforce port-level policy, schedule a demo to see how SecureW2 can modernize your access control infrastructure.

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Frequently Asked Questions

What is a network hub used for?

A network hub is used to connect multiple devices in a local area network so they can communicate with each other. It acts as a central connection point, receiving data from one device and broadcasting it to all other connected devices. Today, hubs are primarily used in legacy environments, small isolated test setups, or lab scenarios where passive traffic capture is needed.

What is the difference between a network hub and a switch?

A network hub broadcasts incoming data to every connected port, regardless of the intended destination. A network switch reads the destination MAC address of each frame and forwards it only to the appropriate port. This means a switch isolates traffic between devices, which improves both performance and security. Switches also support VLANs, port security, and 802.1X authentication; hubs support none of these.

Does a network hub have an IP address?

A standard passive or active network hub does not have an IP address. It operates at Layer 1 of the OSI model and has no awareness of IP addresses or higher-layer protocols. Intelligent (managed) hubs may have an IP address assigned to their management interface, but the hub itself does not use IP addresses to route or forward traffic.

Are network hubs still used today?

Network hubs are rarely used in modern production environments. Switches have replaced them in virtually all deployments because switches offer better performance, traffic isolation, and security at a comparable cost. The main remaining use cases for hubs are legacy environments where upgrading is not yet feasible, and isolated lab or diagnostic setups where broadcasting all traffic to all ports is intentionally useful.

What is the difference between a hub, a switch, and a router?

A hub works at Layer 1 and blindly broadcasts data to every connected port. A switch works at Layer 2, reads MAC addresses, and forwards each frame only to the destination port on the same network. A router works at Layer 3, reads IP addresses, and forwards traffic between separate networks. In short, a hub and a switch connect devices within one network, while a router connects different networks together.

Does a network hub affect speed?

Yes. Because a hub broadcasts every packet to every port and places all devices in a single collision domain, the available bandwidth is shared among all connected devices. As more devices are added, collisions increase and each device gets a smaller share of throughput, which slows the network. A switch avoids this by giving each port its own dedicated bandwidth and forwarding traffic only where it needs to go.