Build a device inventory spreadsheet from a network scan

The insurer wants a list of every device on the office network. The new managed-service provider wants the same list in their onboarding form. And you’d quite like to know yourself how many printers you’re actually paying toner for. A proper asset-management system is overkill for a 25-person office, but a spreadsheet built from a real scan, rather than from memory, is exactly the right size.

This guide builds that sheet on a network you run: one scan, one export, a tidy set of columns, and a monthly routine for keeping it honest. We use Advanced IP Scanner because it’s free for Windows and exports cleanly, but the same approach works with other scanners (alternatives are at the end).

Before you scan: Scan only networks you own or administer, and on client sites get the go-ahead in writing before you start.

Step 1: Decide what the sheet is for

Before scanning, settle on the columns. A sheet that tries to hold everything is abandoned by March. For small offices we keep these:

The MAC address is the key column. IP addresses change with DHCP; the MAC (unless randomized, more on that below) stays with the hardware.

Step 2: Find your address range

On a Windows PC connected to the network:

ipconfig /all

Note the IPv4 Address and Subnet Mask. An address of 192.168.10.23 with mask 255.255.255.0 means the range to scan is 192.168.10.1-192.168.10.254 (a /24). If the office has separate VLANs for Wi-Fi guests, phones or cameras, list each range; you’ll scan them one by one from a machine that can route to them.

Step 3: Run the scan

1. Get Advanced IP Scanner from Famatech’s product site; check /where-to-get for how to confirm the file’s signature before you run it. It offers an option to run without installing, which is handy on a borrowed laptop.
2. Paste the range into the box, for example 192.168.10.1-254.
3. Click Scan. On a /24 with a few dozen devices it usually finishes in well under a minute.
4. Switch the view to show all results so offline addresses don’t clutter it; you only want devices that answered.

Scan at a busy time of day, mid-morning on a weekday, so laptops and phones are present. Printers and switches never leave; people’s devices do.

Step 4: Export and clean up

Use File → Export (the exact menu wording varies between versions) and choose CSV. Open it in Excel or Google Sheets.

Then:

1. Delete columns you won’t maintain (comments, empty fields).
2. Rename headers to match your table from Step 1 and add the manual columns.
3. Sort by IP address. In Excel, a plain text sort puts .100 before .20; add a helper column with the last octet, =VALUE(TEXTAFTER(A2,".",-1)), and sort by that instead.
4. Freeze the header row and turn on filters.

If you’d rather collect data from a command line, a ping sweep with Nmap can write XML you can import:

nmap -sn 192.168.10.0/24 -oX office-scan.xml

On Windows you can also dump the current neighbor table after any scan:

Get-NetNeighbor -AddressFamily IPv4 -State Reachable,Stale |
  Select-Object IPAddress, LinkLayerAddress |
  Export-Csv neighbors.csv -NoTypeInformation

Step 5: Fill in the human columns

This is the part no scanner can do and the part that makes the sheet valuable. Walk the office with a laptop or tablet. For every row, fill in the friendly name, type, location and owner. Use the manufacturer column as a hint: “Hewlett Packard” near the copier is probably the copier.

Anything you can’t identify gets flagged yellow and chased down with the steps in our guide to identifying an unknown device.

While you’re there, decide on addressing. Printers, NAS boxes, access points and anything people type an address into should get a DHCP reservation in the router so their IP never changes. Record that in the Addressing column; it also prevents the problems covered in our IP address conflict guide.

Step 6: Keep it alive

A once-a-year inventory is a historical document. A monthly one is a tool.

1. Once a month, rescan the same ranges and export a fresh CSV.

2. Paste it into a second tab called Scan-YYYY-MM.

3. In the main sheet, add a lookup that checks whether each MAC appeared in the latest scan:

   =IF(ISNA(XLOOKUP(B2, 'Scan-2026-10'!C:C, 'Scan-2026-10'!C:C)), "missing", "seen")

4. Run the reverse check in the scan tab to find MACs that aren’t in the main sheet yet. Those are your new arrivals.

When the office grows past what a spreadsheet can comfortably track, roughly when you have more than one site or need installed-software lists, look at Discovery & Inventory tools such as Lansweeper, which collects this data continuously.

Common mistakes

• Keying rows on IP address. DHCP moves devices around; key on MAC and treat IP as an attribute.
• Ignoring randomized MACs. Phones and some laptops use private MAC addresses per network (second hex digit 2, 6, A or E). Record staff phones by owner instead, or leave them out of the asset sheet and track them in your MDM.
• Scanning only the Wi-Fi. Run the scan from a wired PC too, and scan every VLAN, or you’ll miss cameras and phones on their own segments.
• Letting the sheet live on one laptop. Put it in shared storage with version history.
• Storing admin passwords in the Notes column. Keep a link to the password manager entry instead.

For choosing the scanner itself, see the IP scanners category or our head-to-head of SoftPerfect Network Scanner vs Advanced IP Scanner. SoftPerfect pulls extra fields such as logged-on user and OS over WMI, which saves a lot of walking in Step 5.