LAN Scanner with PRTG

A LAN (Local Area Network) is a type of computer network that connects devices within a limited geographic area, such as a home network, office network, or school network. It allows devices like computers, printers, servers, and other network equipment to communicate and share resources, such as files, applications, or internet access.

LANs typically cover small areas, such as a single building or a group of closely located buildings. They offer high data transfer speeds, usually ranging from 100 Mbps (megabits per second) to 10 Gbps (gigabits per second), depending on the type of network technology used.

A LAN is usually privately owned and managed by an organization or individual. LANs can be either wired (using Ethernet cables) or wireless (using Wi-Fi). Devices on a LAN often communicate through a central device, such as a switch or router.

A LAN scanner is a tool or software like PRTG Network Monitor used to scan and analyze devices and resources on a Local Area Network (LAN). It helps users identify all the devices that are connected to the network, as well as gather information about them, such as their IP addresses, MAC addresses, open ports, and device types. LAN scanners are often used by network administrators and security professionals for monitoring, troubleshooting, and securing the network.

Key functions of a LAN scanner include:

• Device discovery: It detects all devices connected to the LAN, including computers, printers, smartphones, and servers.
• IP scanning and identification: It provides details about the IP addresses (IPv4, IPv6) and MAC addresses of each device.
• Port scanning: As a port scanner, it checks for open or active ports on devices, which can reveal which services are running on a specific machine (e.g., HTTP, FTP, or SSH).
• Network troubleshooting: It helps diagnose network problems by identifying unreachable or malfunctioning devices.
• Security auditing: It can be used to identify potential vulnerabilities, like open ports or unauthorized devices, which might be exploited by attackers.
• Real-time monitoring: Some LAN scanners provide real-time monitoring of network activity, showing when devices join or leave the network.

The key difference between a LAN sniffer and a LAN scanner lies in their functions and how they interact with the network:

LAN scanner (also known as a network scanner or IP scanner)

A LAN scanner is used to discover and gather information about devices on a Local Area Network (LAN), such as their IP addresses, MAC addresses, open ports, and the services they are running. It actively probes the network by sending out requests (e.g., ping requests, ARP requests) to find devices and determine their status or characteristics.

LAN sniffer (also known as a network sniffer or packet sniffer)

A LAN sniffer is used to capture and analyze data packets that travel over the network. It monitors the traffic between devices, allowing you to inspect the content of network communication in real-time. It passively listens to the network by capturing all data packets that are broadcast over the network, without necessarily interacting with the devices themselves. It provides detailed information about the packets' contents, such as source and destination IPs, protocols used (e.g., HTTP, FTP), and even the actual data being transmitted (if not encrypted).

Step 1

Define a network segment or an IP range in your subnet to find network devices via ICMP ping, then launch the Auto-Discovery feature.

Step 2

During the LAN scan, the software determines which types of devices are found and creates sensors for them. Depending on the size of your network (and the number of devices), the automatic network discovery can sometimes take longer to complete.

Step 3

PRTG creates a device tree for all the available devices and uses built-in templates that already include suitable sensors for several types of devices.

In PRTG, “sensors” are the basic monitoring elements. One sensor usually monitors one measured value in your network, for example the traffic of a switch port, the CPU load of a server, or the free space on a disk drive. On average, you need about 5-10 sensors per device or one sensor per switch port.