Port Scanner Tools are pretty useful tools. They help to determine open ports on a network. The open ports will help to send and receive data. This process sends packets to specified ports. It does on specific hosts. Then it analyses the ports. This helps to identify the vulnerabilities.
However, the scan does not occur immediately. First, it identifies a list of active hosts. Second, the hosts are mapped onto their IP addresses. This procedure is called host recovery. However, the procedure begins with a network scan. There is a specific goal behind the port and network scanning.
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What are port scanner tools?
It is an application to probe servers and hosts. The design is made especially for open ports.
It helps in organizing those IP addresses, ports, or hosts. This helps in determining open and vulnerable server locations. Alongside, it diagnoses several security levels. However, port and network scanning can be risky. It tends to reveal any security measures. The presence of these measures is necessary. For instance, the firewall. It is present between the server and the user’s device.
First, a thorough network scan takes place. After its completion, a list of active host compilation takes place. A port scanning may take place. This will help to know any open ports on the internet network. They may get any sort of unauthorized access. A few people can do port scanning and network scanning.
Both IT, administrators, and cybercriminals can make use of it. They use it to check or verify any security policies. Hence, it helps them know the vulnerabilities of a network. Therefore, an attacker can quickly get access. The criminal just needs to know the potentially weak entry points.
The usual plan of an attacker is the following. It first notes the host discovery element in any scamming network. A cybercriminal always does so before execution. Both scans can provide critical tools to attackers. The results can give crucial network security indications. Hence, IT administrators can make use of it. This will help them to present such cyberattacks.
Port and Port numbers
The computer ports serve as central docking points. This helps to understand an information flow from the Internet or a program. It may be information from the computer. Or it may be some other device information. The vice-versa may also take place. It serves as a perfect data parking spot.
One can exchange data later on. There are various ways of doing so. For instance, it may be a software or electronic mechanism. Or, it may occur through a program-related mechanism. Port numbers are necessary for programming and consistency. The number combines with the IP address.
This serves as vital information. The Internet Service Provider keeps it. It helps to fulfill any further requests. The ports may range from zero up to 65,536. This is ranked by popularity. The ports 0 to 1023 are popular port numbers. They are designed especially for internet usage.
However, it is usable for other specialized purposes. The Internet Assigned Numbers Authority (IANA) has the right to administer it. The top-tier companies have a hold on these ports. For instance, MySQL, Apple, MSN, and QuickTime. Here are some standard ports. Alongside, there is a mention of their assigned tasks.
The first is Port 20 (UDP). It holds the file transfer protocol or FTP. This helps to transfer data. The second is Port 22(TCP). This has a secure shell protocol or SSH. It helps in port forwarding, secure logins, and FTP. The third one is Port 53(UDP). It is essentially a domain name system (DNS).
The main aim is to translate a hostname to IP addresses. The fourth one is Port 80(TCP). It is the HTTP for the World Wide Web. Next comes the registered ports. In other words, certain corporations have registered these ports. They range from port 1024 to 49151. Private and dynamic ports follow this. The range is from 49151 to 65536. Nearly anyone can use these ports.
Protocols used in Port Scanning
Usually, two general protocols are used for port scanning. One is transmission control protocol or TCP. The other is the user datagram protocol or UDP. Both methods are used for data transmission from the internet. However, they may have different mechanisms.
TCP is essentially a two-way transmission of data. It is based on connection. It relies heavily on the status of the destination. This is necessary for the completion of a successful send. On the other end, UDP is unreliable. Nor it is connection based.
One may deliver data to the UDP protocol. That too without any being concerned about the destination. Therefore, there is no guarantee of the data. No one knows if it would reach the destination. These two protocols are used for port scanning. Next, we will look at some of the port scanning techniques.
Types of ports in port scanner tools
Several port scans reveal the network or server status. It may fall into one of the three categories.
1. It may be an open port. This port indicates active connections. That is, it means the server is readily accepting connections. Or it may even be datagrams. More so, it responds with a data pack. This indicates it is listening. Besides, TCP or UDP service is necessary for the scan. It even means the chosen service is in full use.
The main aim of port scanning is to find open ports. This may even serve as a victory point for a cybercriminal. Here comes the challenge. What can the IT administrators do? They may build firewalls to protect against any corruption. Hence, it prohibits any strategic attempt to attack. However, it needs to be done without any disruption. This must not hinder the usage.
2. The second type is the closed port. It may indicate a request for the server or the internet. However, there is no available service. That is, no listening port is present in the target host. However, this is still accessible. This is useful to show the host is on a particular IP address. However, these ports must always be under surveillance since they can convert to open ports.
This may cause more threats. This is what IT administrators can do. They can block the closed ports. Further, it should be sone using firewalls.
3. The third type is called filtered ports. This port’s indication is their step. It then sends the request packet. However, the host did not respond. Moreover, it is not even listening. This may mean two things. Either, the firewall blocks the request. Or, it may have been completely filtered out. Suppose the packages don’t reach their destined locations. In this case, the attacker won’t be able to trace more information.
The filter ports answer with error messages. For instance, ‘destination unreachable.’ Or ‘communication prohibited.’
Port Scanning Techniques
Several port scanning techniques are available. Different ones meet different goals. Cybercriminals may also use these techniques. They choose it based on a specific strategy.
Here are some of the most used techniques.
Coming first is the ping scans. It is the simplest available scan. Ping is used for network verification. It verifies whether or not network data packet distribution occurs. It also considers if the distribution to IP address occurs without errors. So what are ping scans? They are an internet control message protocol. It is famous as ICMP.
This automatically requests and sends out several ICMP requests. It serves as a bait to responses on servers. This helps to troubleshoot a ping scan. Or it may disable its ability to use a firewall. Hence, this prevents attackers from tracking the network using pings.
The second technique is the half-open scanning technique. In this technique, the client terminates the connection. It occurs even before a three-way integrated handshake occurs. Majorly, two scanning methods are available under this technique.
SYN scanning method
This one is similar to the full connection method. We will discuss that technique shortly. The SYN stands for the synchronize in short form. The client first receives an SYN message. The message comes from the target host. Straight away, it closes the connection. This is done by sending an RST message. The message gets sent to the target machine.
 Suppose the RST message comes from a target host. In this scenario, the listening port is the target host. This means that the host is in a closed state. Unlike ping scans, three-way handshake restriction prevails here. This method has its benefits. The scanning technique is fast and secure. However, this login occurs less frequently.
One disadvantage of this technique persists. It is necessary to customize the IP packet. This port has to be done by whoever is using it. It may be a sender or receiver. This requires special privileges. Only certain users gain access to such customizations. This is the same for most operating systems.
IP ID Header Technique
This technique is even popular as a dumb scanning technique. This technique is slightly different from the former. It requires a third host for scanning the target host. This is based on the IP value of the IP header field. This decides whether the listening port is open or closed. One may find it in the targeted port.
The third host identification must be made in a specific way. It must be done using little or no traffic at all.
The third type is XMAS scans. These are the most silent scanning technique. They become less noticeable by firewalls.
The next technique on the list is the TCP scanning method. It essentially makes use of the connecting method. It does so in the operating system. This helps in establishing a three-way connection.
Coming to the Stealth scanning technique. This technique is used to prevent logging into a port scan. When the port scan is performed in a host, the user can silently break into firewalls and filters. Here the scan slows down. Hence, port scanning occurs over a long time.
Ultimately, it is a Decoy scanning technique. Here several packets are sent at once in the target host. They are sent to the same port. All the available IP packets are spoofed. In other words, one of them contains the attacker’s IP address. This helps to track the attacker. It makes sure at least one response from the target host goes to the attacker.
One advantage is that it is hard for an administrator to know the attacker. Hence, the results are pretty accurate. Next comes a disadvantage. Several packets are sent to the same port. Thus, the traffic flow increases.
The Port Scanner Tools for Network Administration
We are presenting some of the best port scanner tools to date.
1. SolarWinds Port Scanner
This is the leading company in the creation and establishment of a network. Alongside, it provides IT infrastructure. Here, the primary aim is to develop monitoring software. This port scan tool can be downloaded for free. First, this tool allows scanning the IP address or hostname. After that, it generates a list.
 This is a list of the closed, open, and filter ports. The tool helps to get these ports on the target network. SolarWinds Port Scanner is very easy to use. Just configure the scan profile. This step will help you to initiate scanning. Enter the necessary target information—for instance, hostnames and IP hostnames.
However, certain other configurations are also possible. For instance, configure for the layer four services or ports—for example, TCP, UDP. One may even solve particular problems using this software. The user can resolve hostnames. Here, just a little specific DNS information is necessary. Or, the software can find the MAC address. This will help to know their OS version.
Features of SolarWinds Port Scanner
First, it reduces the running time of a scan. It does so use advanced adaptive timing behavior. Second, the scan configurations get saved in the scan profile. Therefore, the user only needs to scan a specific scan profile. Moreover, no changes in configuration settings would occur further. Thirds, one can write down a batch script. Subsequently, it can be executed at any scheduled time and date.
 Fourth, this port scanner tool supports troubleshooting. It does so when using the command-line interface. Fifth, SolarWinds resolves hostnames with ease. All it does is use the default DNS settings of a local machine. Sixth, the tool sends reports in various formats. For instance, XML, CSV and XLSX. Seventh, one may start, cancel or pause a scan anytime. Isn’t that cool?
 Eighth, while scanning, it determines the operating system. Next, the IANA port name definitions are saved separately. This helps to edit any file with ease. This tool works well on Windows 8 and 10. It works equally well on Server 2012 R2 and 2016.
2. Nmap
This is one of the port scanner tools which is popular and the Swiss Army Knife. It is so for ethical as well as non-ethical hackers. Alongside, it works equally effectively for pen-testers. Nmap stands for Network Mapper in short. Nmap is an open-source tool. It offers excellent flexibility and power.
This occurs anytime when performing any active network reconnaissance. This happens against a target. Customize the IP packets. Next, dispatch it to the specific targets. Therefore allow the scanner to analyses different responses.
Features of Nmap – Port scanner tools
First, it allows scanning a target selection. It can be a hostname, IP range, or a range. Second, this tool helps in port selection. It may be a range or a single port. Third, the scanner detects specific Oss and services. Alongside, perform NSE prints. Fourth is Nmap’s most vital feature. It has different port scan types, for instance, TCP Connect scan.
Some TCP scans and their usages are listed below.
TCP Connect(-sT) helps in a three-way handshake. The responses can be SYN, SYN/ACK, or ACK.
TCP FIN (SF) helps to send FIN. The next thing is the RST response that is equal to the port close.
TCP SYN(sS) send SYN. Alongside, the RST/ACK response means not listening. The other is the SYN/ACK means the receiver is listening.
3. ManageEngine OpUtils
This is the best port scanner. It is a package of tools. This includes tools for network monitoring and management. Some of its facilities are worth mentioning. It is initially a ports scanner. Alongside it is a switch port mapper and IP address manager. The ManageEngine is essentially a free OpUtils version.
Therefore, the latter facilities are not available. However, it has a set of network diagnostic tools. They are pretty useful. They involve TraceRoute and Ping utilities. The free version has an appealing interface. It provides easy access to any package utility.
However, the full package is far more advanced. It provides more such features at once. It offers a free trial of 30 days. After this, the payment of the full package begins. Now you may not want to continue the paid version. Simply switch to the free version. However, this may happen merely after the trial period ends. This scanner is present on Windows and Linux.
Features of ManageEngine OpUtils
To start with, it offers SNMP Ping, ICMP Ping, and Proxy Ping. All this is available for free. The TraceRoute path is present. It helps in further investigations. This tool may even work as a network scanner. It helps in device discovery. Next, it offers a DNS resolver. This helps in the allocation between hostnames and IP addresses.
A MAC resolver is also available. This helps to find the MAC address. One can discover the address of any allocated IP address.
4. Advanced IP Scanner
This is one of the port scanner tools which is easy to use. It is portable enough. This scanner equally serves as a network scanner for Windows. No installation is necessary at all. Just press the play button. Now it has become one of the best port scanners today. The scanner helps to identify a list of network devices. These are informative network devices such as Port, IP, Mac Address, Manufacturer, and OS.
The target scan shows all scan devices at once. It may happen merely when using this scanner. All this happens in a couple of seconds. The tool provides easy access to shared resources. It makes use of HTTPS, HTTP, and FTP. Or it can be done through shared folders. This tool is not out of features at all. It has another fun feature. It is Radmin ports or RDPs.
Features of Advanced IP Scanner
To start with, it provides easy access to shared networks. Second, the tool can even control devices. It happens via Radmin or RDP. Third, one can manage the devices remotely. For instance, remotely switch the computer on or off. Fourth, this port scan tool helps to find MAC addresses. After scanning, the results are sent to a CSV file.
5. Free IP Scanner by Eusing
This is one of those port scanner tools that create free web applications. The applications are mostly miscellaneous. These are exclusively designed for Windows users. The scanner is lightweight. It is a standalone scanner. Free IP scanner checks up to a hundred devices every second. Windows OS fluently supports the tool.
Features of Free IP Scanner
The scanner checks the IPs or range of IPs. It does so to check which one is working. Another distinctive feature is translation. It translates IP to a hostname. The vice versa may also work. Then, it recognizes the open and closed ports.
From there, the tool acquires NetBIOS information. It displays specific device details. They are workgroup, host-name, and the MAC address active logged users. Subsequently, results get exported to the TXT file. Free IP scanner is simple and easy to use. On top of that, its portability makes it a crowd favorite. However, no further functional extensions are possible.
The scanner may scan and find open ports. There is a layer 4 TCP/UDP information. However, it cannot be customized further for more in-depth analysis. The scanning is pretty fast. It does so use multi-thread technology. Multiple target scanning is available. It takes place per second. However, not many resources are consumed.
6. LanSweeper IP Scanner
This port scanner is loved by many. The fundamental reason is its capability to deploy commands and scripts. The tool performs this automatically on many devices. More so, this was carried out at the same time. It makes use of an integrated deployment feature. This deploys software automatically. Alongside, it executes device commands as shown in inventory.
This tool is multi-functional. It goes far beyond simple scanning. LanSweeper allows the user to get deeper scan details. It also finds out issues instantly. Lastly, it fixes them proactively. Network information is taken from flowing protocols. HTTP, WMI, FTP, SNMP, SSH.
Features of LanSweeper IP Scanner
The first feature obtains its capacity of inventorying. Second, IP scanning occurs. It may occur automatically. Or it may occur on demand. Third, CSV files are used to deliver the files. Remote actions are customized—for instance, a remote shutdown. The scanner also contains a Wake-On-LAN manager. There are other such features of this scanner.
For instance, it helps to find a MAC address. It may even help to look for logged-on users. The tool also helps to know device up-times and user accounts. There is a free and a paid version. The free version allows you to gain detailed information. It can do so for up to 100 devices. Most importantly, it does all this at once.
The user interface is simple and effective. It can rediscover the entire subnet at once
7. NetCat
This port scan tool is similar to Nmap. Most hackers prefer it. NetCat is a pretty versatile scanning tool. It is not just an IP scanner. This scanner goes beyond that. NetCat is a tiny Unix network analyzer. Many hackers use this. Besides, it can be used against hackers. This is performed for several reasons.
It is compact and portable. The networking tool is rich in features. It is utilized primarily for debugging and investigation. Any kind of connection can be generated using NetCat. The tool writes to network connections. It also reads the data from those connections. TCP or UDP is used for connecting.
Features of NetCat – One of the best port scanner tools
To begin with, NetCat provides inbound and outbound connections. It makes use of the TCP and UDP ports. The second feature is pretty unique. It helps to develop network tunneling, for example, tunneling UDP to TCP. Thirdly, the scanner has a built-in scanning capacity. The usage options of NetCat are very advanced.
They are hex dump and buffered send mode. Specific codes are provided for responding and parsing. They are the RFC854 telnet codes. The scanner provides complete DNS forwarding. Alongside, it allows reverse checking. All this occurs with appropriate warnings. NetCat makes use of local source port. Or it a locally sourced network address. It even reads the command line arguments. Hence, it provides standard input.
NetCat can equally create backdoors. They help to get easy target access. The one can first scan the open ports. Then listen and direct them to target hosts. The scanning tool can even transfer files from the target. It is capable of connecting to remote services. It does so from any port or service.
8. Angry IP Scanner
This port scanner tool is popular as ipscan. Angry IP scanner is available for free. Otherwise, this network scanner is open-sourced. It works on most operating systems—for example, Windows, Linux, Mac OSX. The design of this tool is comparatively simple. It includes ultra-light software. No installation is necessary. This makes the device more portable. Also, it is easy to use this scanner.
The Scanner pings at the fundamental level. This indicates the device network or device is alive. Like other scanners, it can be acceptable Mac addresses. Moreover, it helps to resolve hostnames and scan ports. Right away, you may want to obtain comprehensive information. So, make use of the plugins.
Features of Angry IP Scanner
To start with, the tool can scan both public and Private IP addresses. Furthermore, it can receive NetBIOS information on a device. Besides, it can customize openers. Angry IP can also detect web servers. The scan results can be exported. It can be achieved using specific formats. CSV, IP-Port, XML, TXT are the usable formats.
This port scan tool uses a multi-thread approach. It is used for faster scanning. The tool has certain default fetchers. They are Ports, Ping, and Host-name. However, more fetchers are necessary for extracting further information. Make sure to use plugins for this purpose.
Angry IP scanner runs solely on GUI. However, the user can call the CLI. It will help to come up with different software options. This scanner also comes with a command-line interface.
9. Slitheris Network Discovery
This scanner tool originated from Komodo elaborates. It is a premium scanner. Furthermore, it is based on the Windows operating system. There are two versions of this advanced network scanner. The free version can search for about 50 network devices. This capacity can be extended. The user just needs a premium license for it. Using Slitheris, scanning goes to the next level.
This scanner is extraordinarily active and fast. It rapidly gathers information. Many such scanners cannot do it so swiftly. The tool collects needed information from target network devices. Further, this gets done without any agent or credential. Like Angry IP scanner, it makes use of the multithread approach. This helps to find out pingable devices quickly. Also, it uses ARP rings. This helps to look for any hidden devices.
Features of Slitheris Network Discovery
Initially, the visual ping sweep happens in real-time. It shows what the ping sweep performs. Here, it is done with the visual matrix. This scanner allows fingerprinting and OS detection. Hence, one can detect many Windows OS versions. This occurs without the need for any credentials.
Slitheris is an expert at identifying the devices. It can be a mobile, printer, or a virtual machine. Or it may be a server or workstation. This port scanner tool will detect every device with ease. Use this scanner to determine the age of any device. Make sure you make use of the Mac address.
It provides SMB security. It is the Server Message Block security. The scanner alarm goes off when it is enabled or disabled. It also helps to detect any stealth device. An ARP cache is used here. It helps to find unsingable services. Lastly, a portable version of this scanner is present.
10. MyLanViewer Network/IP Scanner
This is an extremely comprehensive network scanner. The scanner is exclusively made for Windows OS. This tool scans the target network at a basic level. It will reveal the Mac address, IP, OS version, and NIC vendor. It even shows the locked folders. Besides, the shared folders are also seen here. These may be from wired and wireless devices. They come in a list that is easy to read.
MyLanViewer is capable of monitoring any network. It may even be a hidden network. Alongside, it informs the user when a current device appears.
Features of MyLanViewer Network/IP Scanner
This port scan tool carries out remote actions. They include a reboot and remote shutdown, hibernate or sleep. It allows the user to find any Mac and IP addresses. One can even find shared folders employing this tool. Besides, the folders may be from wired or any wireless network.
One can even get hold of the DHCP servers through this. It is capable of terminating user sessions. The scanner reveals many netstat information as well. The scanner monitors the IP addresses. Like so, any changes made on the computer is easily detected. The interface of MyLanViewer is user friendly. Lastly, it works efficiently on Windows XP, 7,8, 2000, 2003, and Vista.
Port scanning as a means of a cyberattack
Port scanning remains the most common method of attack. Attackers employ this tactic pretty often. They look for vulnerable networks to breach. SANS Institute has identified this.
For cybercriminals, port scanning marks the preliminary step. First, the port scan. This helps to scope out the security levels. They do so for various organizations. Next, they determine which organization has the most robust firewall. Alongside, they determine which one has the most vulnerable server network.
There are a couple of TCP protocol techniques. These assist the attackers in concealing their current location. Furthermore, they use the ‘decoy’ traffic for port scanning. Thus, the address location is not revealed to the target. Cybercriminals tend to probe the systems and networks. They do so to check how each port would react. That is, whether it is open, close, or filtered.
For example, the open and closed responses. These alert hackers about one fact. That is, your network is receiving the end of the scan. Subsequently, it becomes easier to detect the operating system. Also, they detect the operation type and security level. Port scanning is an old technique today. Therefore, it needs a lot of security changes. It is necessary to keep the threat intelligence up-to-date. Security and protocols keep evolving daily. Thus, maintaining security updated is crucial.
Firewalls and port scan alerts must be used to monitor your port traffic. This will prevent attackers from gaining any unauthorized entry. Therefore, this can be the best possible use of a port scan.
Concluding
The open ports are essentially gateways to networks. They can pose severe threats if not managed safely. This is where port scanning software comes into play. There is a toolbox of security and network administrators. It contains all port and service scanners.
This helps in the identification of open ports. Thus, vulnerabilities can be controlled effectively. Several free online scanners are available. However, each of the ten chosen port scan tools stands out. They are rich in their effectiveness, portability, flexibility, feature-richness, and cost-efficiency. Hence download a copy of any scanner today. Then scan your network. This will aid you in preventing any future cyberattacks.
