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Network Scanner

Scan your local network to discover connected devices using ping probes and port scanning.

iPhoneiPadMacApple Vision ProApple TVApple Watch

Overview​

Network Scanner probes every address on your local network to find responsive devices. It sends a small test packet (called a "ping") to each possible address on your network and reports which ones respond. Optionally, it can also check for open ports on discovered devices and use Bonjour hints to identify device types. This is useful for seeing what is connected to your home or office network, finding the IP address of a specific device, or checking whether a device is reachable.

Table of Contents​

Permissions​

Network Scanner requires Local Network permission to send probes to devices on your network. The first time you use this tool, your device will ask you to allow Lirum to find and communicate with devices on your local network. You must grant this permission for the scanner to function.

If you previously denied this permission, go to your device's Settings, find Lirum in the app list, and turn on Local Network.

Hero Card​

The hero card at the top of the screen shows scan controls and your current network context:

  • Status Pill -- a colored badge showing the scanner's state (Idle, Scanning, Finished, Stopped, or Error).
  • Start / Stop Button -- tap Start to begin scanning your network. While a scan is in progress, tap Stop to end it early.
  • Clear Button -- removes all discovered devices and resets the results.

Network Context​

The hero card also displays three tiles that describe the network you are currently connected to:

  • Local IP -- your device's IP address on the current network (e.g., 192.168.1.42). This is the address other devices on your network see when communicating with your device.
  • Subnet Mask -- defines the size of your local network. A common value is 255.255.255.0, which means there are up to 254 possible device addresses on your network. The subnet mask tells the scanner which range of addresses to probe.
  • Gateway -- the IP address of your router. The gateway is the device that connects your local network to the internet. It is usually the first or last address in your network range (e.g., 192.168.1.1).

Progress Card​

While a scan is running, the progress card shows real-time updates:

  • Scan Progress -- a percentage bar showing how much of the network has been scanned so far.
  • Hosts Scanned -- the number of addresses that have been probed out of the total.
  • Current Host -- the IP address currently being probed.
  • Responsive Hosts -- how many addresses have responded to the ping. These are the devices that are online and reachable.
  • Open Ports -- how many open TCP ports have been found across all responsive devices (only shown when port fingerprinting is enabled).
  • Bonjour Hints -- how many devices were identified through Bonjour discovery in addition to the ping scan (only shown when Bonjour assistance is enabled).

Scan Controls​

Below the hero card, several settings let you customize how the scan operates:

  • Probe Timeout (0.2 to 3.0 seconds) -- how long the scanner waits for a response from each address before moving on. A shorter timeout makes the scan faster but may miss slow-responding devices. A longer timeout is more thorough but takes more time. The default is a good balance for most networks.
  • Parallel Workers (1 to 64) -- how many addresses the scanner probes simultaneously. More workers means a faster scan, but using too many on a slow network or older device may reduce accuracy. A moderate value (8 to 16) works well in most situations.
  • Show Unresponsive Hosts toggle -- when enabled, addresses that did not respond are also shown in the results list. This is on by default; turn it off to keep the list short on large networks.
  • Bonjour Assistance toggle -- when enabled, the scanner also uses Bonjour discovery alongside ping probes. This can help identify the names and types of Apple devices and other Bonjour-enabled hardware on your network.
  • Port Fingerprinting toggle -- when enabled, the scanner checks a set of commonly used TCP ports on each responsive device. This can reveal what services a device is running (for example, a web server on port 80 or a file sharing service on port 445). Port fingerprinting makes the scan take longer but provides richer results.

Device Cards​

Each discovered device appears as a card with the following details:

  • Icon -- a contextual icon representing the detected device type (when identifiable).
  • Host Title -- the device's hostname or a descriptive label, if available.
  • IP Address -- the device's IP address on the local network.
  • Status Badge -- a colored indicator showing how the device was found:
    • Reachable (green) -- the device responded to the ping probe.
    • Bonjour (blue) -- the device was found through Bonjour discovery.
    • Error (red) -- the scanner encountered an error trying to reach this address.
    • No Response (orange) -- the address did not respond (only visible when "Show Unresponsive Hosts" is turned on).
  • Device Type -- when identifiable, shows what kind of device was detected (e.g., router, printer, computer).
  • Open TCP Ports -- a list of open ports found on the device (only shown when port fingerprinting is enabled). Common ports include:
    • 22 -- SSH (secure remote access)
    • 53 -- DNS (name resolution)
    • 80 -- HTTP (web server)
    • 139 -- NetBIOS (Windows file/session)
    • 443 -- HTTPS (secure web server)
    • 445 -- SMB (file sharing)
    • 548 -- AFP (Apple file sharing)
    • 631 -- IPP (internet printing)
    • 9100 -- Printer raw (direct printing)
    • 62078 -- iPhone sync (USB/iTunes sync)
  • Hostname -- the device's network hostname, if available.
  • Bonjour Metadata -- additional information discovered through Bonjour, such as the device's advertised service names and model information.

Log Section​

A collapsible log at the bottom of the screen records each step of the scan in chronological order. Log entries are timestamped and include probe results, errors, and discovery events. This can be helpful for troubleshooting when a device you expect to find does not appear.

Notes And Limitations​

  • Network Scanner only scans your current local network (the subnet you are connected to). It does not scan across the internet or reach devices on other subnets.
  • Some devices are configured to ignore ping requests (ICMP echo) for security reasons. These devices will appear as unresponsive even though they are connected and functioning normally. Enabling Bonjour Assistance may help discover such devices if they advertise Bonjour services.
  • Firewalls on your network or on individual devices may block the scan probes, leading to incomplete results.
  • The scan duration depends on your network size, the probe timeout, and the number of parallel workers. A typical home network scan with default settings completes in under a minute.
  • Port fingerprinting only checks a predefined set of common TCP ports. It does not perform a comprehensive port scan of all 65,535 possible ports.
  • On very large networks (for example, a /16 subnet with over 65,000 addresses), the scan is automatically truncated to the first 1024 addresses for safety, so only a subset of hosts is probed.
  • The Local Network permission is required. Without it, the scanner cannot send probes to other devices.
Last updated on by Rogerio Hirooka