LAN Device Scanner

Tool Introduction

"LAN Device Scanner" is a free online tool designed to help users quickly and accurately discover all online devices within their local area network. By entering a target IP address range, this tool can scan and identify active hosts in the network, their corresponding IP addresses, MAC addresses, and attempt to retrieve hostnames, making it a powerful assistant for network management, security auditing, and troubleshooting. Whether you want to find unknown devices, verify network configurations, or monitor device online status, this tool provides a convenient and efficient solution.

How to Use

1. Enter the LAN IP address range you want to scan in the input box. Multiple formats are supported, such as CIDR notation (e.g., 192.168.1.0/24), IP address range (e.g., 192.168.1.1-192.168.1.254), or a single IP address (e.g., 192.168.1.100).
2. Click the "Start Scan" button, and the tool will begin probing IP addresses within the specified range.
3. After the scan is complete, the results will be displayed in a list or table format, including detailed information such as the IP addresses of discovered online devices, MAC addresses, possible hostnames, and device status.

Usage Example

Example Input:

192.168.1.0/24

Expected Output:

IP Address	MAC Address	Hostname (if available)	Status
192.168.1.1	00:1A:2B:3C:4D:5E	Router-Gateway	Online
192.168.1.10	F0:E1:D2:C3:B4:A5	MyPC	Online
192.168.1.100	01:02:03:04:05:06	MyPhone	Online
192.168.1.150	AA:BB:CC:DD:EE:FF	SmartTV	Online
192.168.1.200	CC:FF:EE:DD:BB:AA	NetworkPrinter	Online

Specific Operation Demo:

1. In the tool's IP range input box, enter 192.168.1.0/24.
2. Click the "Start Scan" button.
3. Wait a few seconds to tens of seconds (depending on the network size and your network environment), and the scan results table will automatically appear at the bottom of the page.
4. You can view the MAC address and hostname corresponding to each IP address to identify all devices in the network.

Frequently Asked Questions

• Q: What IP address range formats does this tool support? A: This tool supports various common IP address range formats such as CIDR notation (e.g., 192.168.1.0/24), IP address range (e.g., 192.168.1.1-192.168.1.254), and single IP addresses (e.g., 192.168.1.100).
• Q: What is the scanning principle? A: This tool primarily uses various network detection technologies, such as sending ARP requests, ICMP Echo requests (ping), and/or TCP port scans, to determine if a device is online at a specified IP address and attempts to obtain its MAC address and hostname.
• Q: Why were some devices not scanned? A: Possible reasons include: the device is offline, the device has a firewall blocking detection requests, the tool cannot scan other subnets across a router, or the scan time was insufficient. Please ensure the device is online and not blocking ICMP/ARP requests.
• Q: Can I scan devices on a public network (internet)? A: No. This tool is designed specifically for local area networks (private networks), aiming to scan devices within the private network you are currently connected to (such as a home network, office network). Scanning public networks usually requires more complex tools and permissions.

Precautions

• Please ensure you have legal authorization for the LAN you are scanning to avoid unauthorized scanning activities.
• Scanning large IP address ranges may take a long time, please be patient.
• The accuracy of scan results may be limited by network firewall settings, device online status, and network topology. Some devices may not be fully identified due to security settings.
• This tool is an online tool, and your scan requests will be executed through a server. Please do not use it for illegal purposes.
• Do not use this tool for malicious attacks or to infringe on others' privacy.

What is a LAN?

A Local Area Network (LAN) refers to a network system where multiple computers and network devices are connected through transmission media within a limited area, enabling resource sharing and data communication. It typically covers a small area, such as a home, office, school, or within an enterprise. Compared to a Wide Area Network (WAN), a LAN has characteristics such as high transmission speed, low latency, and relatively simple management. It is the most common type of network in our daily lives.

Difference Between IP Address and MAC Address

Both IP addresses and MAC addresses are unique identifiers used to identify network devices, but they differ in their layer and function within the network protocol stack:

• IP Address (Internet Protocol Address): Located at the network layer (Layer 3 of the OSI model), it is primarily used to identify a logical address in the network. It can be routed across networks and is the basis for inter-network communication. IP addresses are divided into IPv4 and IPv6, and can be dynamically assigned (DHCP) or statically configured. When a device moves from one network to another, its IP address may change.
• MAC Address (Media Access Control Address): Located at the data link layer (Layer 2 of the OSI model), it is a physical address embedded in the hardware of a network interface card (NIC) at the time of manufacture, and is globally unique. MAC addresses are primarily used to identify devices within a local area network to ensure accurate transmission of data frames. It is usually unchangeable; even if the device moves to a different network, the MAC address will not change.

In short, an IP address is the "house number" in the network world, which can change; a MAC address is the "ID card number" of the network card, which is a fixed hardware identifier.