Network Scanning

Overview

When you click Scan Network, NetMap Pro runs five discovery passes in sequence. Each phase uses a different protocol to find devices that might be invisible to the others. The result is a comprehensive device list with manufacturer identification — not just a list of IP addresses.

The 5 Phases

Phase 1: ARP / Ping Sweep

NetMap Pro sends ARP requests (on the local subnet) and ICMP ping packets to every address in the target range. This is the broadest and fastest scan — it finds any device that responds to basic network traffic. Most wired devices respond to ARP even if they block ping.

• Discovers IP address and MAC address pairs
• Works for any device connected to the network
• Fastest phase — completes in a few seconds

Phase 2: SSDP / UPnP Discovery

Sends a multicast SSDP (Simple Service Discovery Protocol) query. Devices that support UPnP respond with their service descriptions, which often include the device model, manufacturer, and friendly name.

• Common on media players, smart TVs, Sonos speakers, and NAS devices
• Can provide device model names and icons
• May work across subnets if the router forwards multicast — don't rely on it for cross-VLAN discovery

Phase 3: mDNS / Bonjour

Queries the multicast DNS responder on the network. Apple devices, printers, Chromecasts, and many IoT devices advertise themselves via mDNS (also known as Bonjour or Avahi).

• Great for Apple devices, printers, and Chromecast
• Provides human-readable service names
• Discovers devices that block ICMP ping

Phase 4: OUI Manufacturer Lookup

Every network adapter has a MAC address. The first three bytes (the OUI — Organizationally Unique Identifier) identify the manufacturer. NetMap Pro checks each MAC against a database of 500+ manufacturer prefixes to identify the device brand.

• Identifies manufacturer for any device with a known MAC prefix
• Database includes 44+ manufacturers common in AV installations
• Covers Crestron, Lutron, Sonos, Axis, Hikvision, Samsung, LG, Onkyo, and more

Phase 5: HTTP Probe

Attempts an HTTP connection to discovered devices on common ports (80, 443, 8080). Many network devices serve a web management interface that returns identifying headers or page titles. This data helps identify the device when OUI alone isn't specific enough.

• Reads the HTML title tag from web interfaces (shown in device details)
• Captures server headers for additional identification
• Useful for managed switches, routers, and IP cameras

Scan Tips

Understanding Scan Results

After the scan completes, the Devices tab shows a table with every discovered device. Each row includes:

Click any device row to expand it and edit all fields including location, notes, and reserved IP. Use Copy IP / Copy MAC buttons for quick programming and documentation tasks.

Re-Scanning

You can run additional scans at any time. New devices are added to the list, and existing devices are updated with fresh data. Devices you've already named and categorized keep their labels — the scan only updates network-level fields (IP, MAC, manufacturer).

Troubleshooting

Scan finds no devices

• Check your network connection — make sure your laptop is actually connected to the target network.
• Verify the subnet — the auto-detected subnet should match the network you're scanning.
• Try Ethernet — some Wi-Fi networks have client isolation enabled, which blocks device discovery.
• Check Windows Firewall — temporarily disable it to test if it's blocking ARP/ICMP traffic.

Scan misses some devices

• Devices must be powered on — use the Phone Companion to capture MACs from unpowered devices.
• Some devices block discovery — Crestron processors and enterprise switches often disable ICMP. Run Connection Doctor on known IPs to check connectivity.
• VLANs — devices on a different VLAN won't appear. Scan from each VLAN, or add those devices manually.
• Run a second scan — some devices are slow to respond and get picked up on the next pass.

For more troubleshooting, see the Troubleshooting & FAQ page.

Next Steps

After scanning, you'll typically:

• Name and organize devices — click any device row to edit. See Project Management.
• Assign IPs, then snapshot - set reserved IPs by device type, save a snapshot, then run safe push checks. See Router Integration.
• Run Connection Doctor — select devices and verify they're healthy. See Connection Doctor.
• Export a report — generate a PDF or CSV for the client. See Exporting & Reports.