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TechKnowSurge Catalog Videos Scanning and Probing
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Scanning and Probing

Network scanning identifies devices and assesses their state across an infrastructure, supporting asset discovery, vulnerability assessment, and uptime monitoring. Tools like Nmap, PRTG, and Pingdom each serve distinct scanning and probing purposes in a professional network environment.

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About this video

Network scanning is a foundational practice in network management and cybersecurity, used to detect what devices exist on a network and to assess the features or state of those devices. The process typically begins with a ping sweep, which sends ICMP requests across an IP range to identify live hosts. Once active devices are located, port scanning can reveal which services are running, helping administrators determine device types — such as identifying a machine as a Windows-based web server based on its open ports. Organizations scan their networks for a range of operational and security purposes, including asset inventory, uptime and availability monitoring, service auditing, and network mapping. Discovering unauthorized devices or unnecessarily open services is a direct outcome of routine scanning, making it a critical component of vulnerability management. Tools commonly used for this work include Nmap for on-demand host and service discovery, and PRTG for automated, scheduled scanning across defined IP ranges with ongoing monitoring capabilities. Beyond internal scanning, external probing tools like Pingdom provide continuous availability testing from distributed cloud infrastructure across multiple regions and countries. While probing differs slightly from scanning in its mechanics, it serves a complementary purpose — verifying that services remain reachable from outside the network and triggering alerts when downtime is detected. Together, internal scanning and external probing give network and security teams a comprehensive view of infrastructure health and exposure.

What you'll learn

What's covered

Network Scanning

Aligned to

CompTIA CySA+
2.1 Given a scenario, implement vulnerability scanning methods and concepts.
2.2 Given a scenario, analyze output from vulnerability assessment tools.
EC-Council CEH
2.2 Scanning Networks
NIST CSF
ID.AM-01 Inventories of hardware managed by the organization are maintained.
DE.CM-01 Networks and network services are monitored to find potentially adverse events.
NIST 800-53
RA-5 Vulnerability Monitoring and Scanning
CompTIA Security+
4.4 Explain security alerting and monitoring concepts and tools.

Key terms

Internet Control Message Protocol
ICMP
A network layer protocol used to send error messages and operational information about network conditions.
Port Scanning
A technique used to discover open ports and services available on a networked device.
IP Address
A numerical label assigned to each device connected to a network that uses the Internet Protocol.
Vulnerability Assessment
The process of identifying, quantifying, and prioritizing vulnerabilities in a system.
Asset
Any resource of value to an organization, including hardware, software, data, and personnel.
Ping Sweep
A network scanning technique that sends ICMP echo requests to a range of IP addresses to identify which hosts are active on a network.
Network Mapper
Nmap
Network Mapper is an open-source security scanner used for network discovery, port scanning, service detection, and OS fingerprinting to assess the attack surface of networked systems.
PRTG
A network monitoring platform that scans and continuously monitors network devices, services, and bandwidth across an IP range.

Topics

Network Scanning Port Enumeration Nmap Asset Discovery Vulnerability Assessment Network Monitoring Networking

Transcript

Scanning is a way that we can help identify equipment on our network and discover issues on our network. The word scanning just means detecting a feature or a state, and what we're doing on our networks is we're scanning the network to determine, number one, what equipment is out there, but also, when we find equipment, what are the features or state of that equipment.

What a scan looks like

If we're doing something like vulnerability scanning or asset inventory, we may start out with a scan. There are multiple ways that the scanning looks, but one of the ways is, let's say we set up some sort of scanning software, and then what we can do is we can scan the network. Maybe we start out with a ping sweep, and so we're going to ping all of the different addresses within range and we discover all of the equipment. So now one thing that we've done is we've discovered equipment.

Then what we can do is we can do another scan of ports on the equipment, and we can see what type of equipment it is. So if we scan this right here and realize that certain ports are open, we may discover, well, that's a Windows machine, and maybe even more specifically it's a web server. So we can scan to figure out what is happening within our network.

Reasons to scan

Some reasons why we might scan are to record uptime, downtime and availability. Maybe it's to discover assets that are on our network, to find equipment that's on our network. Maybe it's to find services that are open that maybe should be turned off and should be closed. Or maybe we're just figuring out the uptime of certain services, or maybe it's to create a network map.

When it comes to scanning, it could be really any services that we want to figure out if they're up and running. One of the basic ones is ICMP. We use ICMP a lot just to figure out if equipment is up and running and functioning, and if we get a ping back, that means that that IP address is live. But we could be scanning for a lot of other services as well.

Examples of scanning and probing tools

Here are some examples that will do this. Nmap is a program that we can execute on our local machine to do scans to figure out what IP addresses are out there and what equipment is out there.

We could also use PRTG. PRTG is a monitoring software, and one of the first things we could do is we could tell it our IP range, and it can do a scan of that whole network to figure out what are all of the different pieces of equipment and what should it be monitoring. We could even set it up to do automatic scans on a regular basis to find new pieces of equipment on our network.

I've also used ping, which is external to the system, and it will test to see if a web page is up and running, and it will test it from all around the world, so this is a hosted solution there.

I also gave an example of using something like Pingdom, which tests out the connectivity of a network, kind of like, is this web page still up, is this web page still up, and continues to test it. I don't really consider that scanning, but it's probing, and it's along the same lines, where it's continually testing to make sure that the website is up, and then if it does go down it can notify you. It also can test it from a lot of different resources. It's a cloud offering, and so it can test from a lot of different regions, in a lot of different areas, a lot of different countries. So you go in there and specify, I want to test from all of these different countries.

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