Your first scan with Network Scanner

Set up the lab notebook

From this lesson on, you will produce files that later lessons need. Create the folders once, now, so nothing ends up in Downloads:

New-Item -ItemType Directory C:\LANScan365\results, C:\LANScan365\exports, C:\LANScan365\notes -Force

If you have not installed Network Scanner yet, do that first — the install guide covers it, including the preference settings this course assumes. Scanning does not need administrator rights, so run the program as your normal account unless a lesson says otherwise.

A quick tour of the window

Network Scanner has a classic Windows layout. Across the top are the menus — File, Target, Address, Scan, Resources, Tools, View and Help — and a toolbar of large icons for the actions you will use most: adding targets, starting and stopping scans, searching, filtering and preferences.

Below the toolbar the window splits in two. The left pane has two tabs: Scan, where you pick targets and services, and Filter, which you will use in lesson 5. The right pane is the results tree, with a Resource name filter above it and columns for Name, Address, Latency and Comment.

Build the target list

The Target box at the top of the Scan tab holds a named set of targets (the first one is called “Default”), and below it a checklist of ranges, expressions and lists. Only the ticked entries are scanned, so you can keep everything in one set and choose per scan.

Add Kestrel’s three targets, using the plan from lesson 2:

1. A range for the staff segment

   Choose the add-range command (toolbar or Target menu). Name it Staff, start 172.16.40.1, stop 172.16.40.254.

2. An expression for servers and cameras

   Add an expression named Servers and cameras: 172.16.42-43.1-254. One line covers two segments.

3. A list of the devices that must always answer

   Add a list named Fixed devices and type the names from your map: KT-GW, KT-DC1, KT-FS1, KT-NAS, KT-PRN1, KT-PRN2, KT-NVR. A list scans by name, so it also tests that DNS resolves each one.

Choose what to look for

The Services box decides what the scanner asks each live host about:

For the first pass, tick Netbios (Samba) only and leave Check access off. There are three reasons. It is the fastest scan, so you get a result in minutes. It answers the lesson’s real question — does the network match the map? — without drowning you in detail. And it touches the network lightly: listing shares is something every Windows PC does all day, while access checks and FTP logins are more visible. You will turn the others on deliberately in lessons 8 and 9.

First scan: find the machines and their shares. Access, FTP and web come later, one question at a time.

Run, watch, stop

Tick all three targets and start the scan. Network Scanner is multi-threaded, so it checks many addresses at once; on a few hundred addresses a NetBIOS scan usually takes well under a minute. The status bar at the bottom shows progress counters and the elapsed time.

If something is clearly wrong — you ticked the wrong range, or the scan is crawling — stop it. Network Scanner stops a scan instantly, and whatever was found so far stays in the tree.

Save the first result

Network Scanner can save the whole result — targets, computers, shares, comments — to a file and load it again later with File → Load. Use File → Save as… and put it in C:\LANScan365\results\ with the date and scope in the name, for example 2026-09-18 netbios all-scopes.

This file is your baseline. In lesson 7 you will load it next to a later scan to see what changed. Save a copy of it somewhere that is backed up.

A first look at what came back

Lesson 5 is all about reading the tree, but do one thing now: compare it with your map. At Kestrel the first NetBIOS scan found:

Write the same kind of comparison for your network. You are not judging anything yet — just noting what matches the map and what does not.

Exercise: your first saved scan

• Add a range, an expression and a name list built from your own address plan.
• Run a NetBIOS-only scan with Check access switched off.
• Save it as C:\LANScan365\results\<date> netbios all-scopes.
• In C:\LANScan365\notes\first-scan.md, list each fixed device from your map as found / not found, and anything found that is not on the map.
• Note how long the scan took; you will use it to judge tuning in lesson 6.