Which tool is used to provide a list of open ports on network devices?

Network complexity is rapidly increasing with the addition of non-traditional devices gaining access to organizational networks. Singular purpose devices made available through the Internet of Things (IoT) offering has increased network complexity even further with the ease of adding said devices to the network and sometimes without the knowledge of a system administrator. Hence the following received question: " How do I ensure all the appropriate ports are closed with all these devices being added to my network?" In scenarios like these, tools such as azure iot security architecture To help with this, the following PowerShell script will provide a rudimentary analysis report on what ports of what IPs are currently open. This report can be used as a great starting point to highlight probable attack vectors that could occur and the beginning to a conversation on additional security tool adoption. Lets begin. • Run PowerShell Run PowerShell Force AzureAD Password Sync • Specify the $portvalue to scan: $port = (80) • Specify the $networkvalue to scan: $network = (192.168.0) • Specify the $rangevalue to scan: $range = (1..254) • Enable silent scan (without error reporting) of said network: $ErrorActionPreference= ‘silentlycontinue’ • Calling the IP addresses one by one from the desired range and displaying the percentage to complete: $(Foreach ($add in $range) ) | Out-File C:\reports\portscan.csv Again this is a rudimentary report output that can be utilized to begin the conv...

You might describe ports as gates into your hardware. These gateways exist in the network and can be points of vulnerability. Your hardware is constantly managing multiple activities and tasks at once, and many of these will require network access. The issue with this is usually devices only have a single network interface. Ports are the solution to this issue, allowing multiple processes and activities to have access to a shared network interface. In practice, port use looks something like this: imagine a server is running an FTP server and a web server simultaneously. This is a normal and frequent combination. When the server gets an inbound request, the operating system has to decide whether to send the request to the FTP or web server. In this instance, ports would determine where the request goes, guiding a web server request through port 80 and an FTP server request through port 21. Port numbers are set and correspond to the function for which each port is responsible. Commonly Used Ports These are the most commonly used ports, alongside their port numbers. Bear with me, because the list is hefty, but hopefully it will serve as a useful reference guide for you. • 20: File Transfer Protocol (FTP) data channel. • 21: File Transfer Protocol (FTP) control channel. The commands port. • 22: Secure Shell (SSH). Remote management protocol OS. • 23: Telnet, or terminal network, for protocol implementation text interface across a network. • 25: Simple Mail Transfer Protocol (S...

Contents • How to Use netstat Command in Linux • List All Ports and Connections • List All TCP Ports • List All UDP Ports • List Only Listening Ports • Display Statistics by Protocol • List Network Interface Transactions • Display Extended Kernel Interface Table • Display Masqueraded Connections • Display PID • Find Listening Programs • Display Kernel IP Routing Table • Display IPv4 and IPv6 Group Membership • Print netstat Info Continuously • Find Unconfigured Address Families • Display Numerical Addresses, Host Addresses, Port Numbers, and User IDs • Find a Process That Is Using a Particular Port • List All netstat Commands The first list in the output displays active established internet connections on the computer. The following details are in the columns: • Proto – Protocol of the connection ( TCP, • Recv-Q – Receive queue of bytes received or ready to be received. • Send-Q – Send queue of bytes ready to be sent. • Local address –Address details and port of the local connection. An asterisk (*) in the host indicates that the server is listening and if a port is not yet established. • Foreign address– Address details and port of the remote end of the connection. An asterisk (*) appears if a port is not yet established. • State –State of the ESTABLISHED, LISTENING, CLOSED or blank . The second list shows all the active " Unix Domain" open sockets with the following details: • Proto– Protocol used by the socket (always unix). • RefCnt– Reference count of the number of at...

Introduction to Port Scanning While Nmap has grown in functionality over the years, it began as an efficient port scanner, and that remains its core function. The simple command nmap scans the most commonly used 1,000 TCP ports on the host , classifying each port into the state open, closed, filtered, unfiltered, open|filtered, or closed|filtered. What Exactly is a Port? Ports are simply a software abstraction, used to distinguish between communication channels. Similar to the way IP addresses are used to identify machines on networks, ports identify specific applications in use on a single machine. For example, your web browser will by default connect to TCP port 80 of machines in HTTP URLs. If you specify the secure HTTPS protocol instead, the browser will try port 443 by default. Nmap works with two protocols that use ports: TCP and UDP. A connection for each protocol is uniquely identified by four elements: source and destination IP addresses and corresponding source and destination ports. All of these elements are simply numbers placed in the headers of each packet sent between hosts. The protocol is an eight-bit field, which specifies what type of packet is contained in the IP data (payload) section. For example, TCP is protocol number six, and UDP is 17. IPv4 addresses have a length of 32-bits, while ports are 16-bits long. IPv6 addresses are 128-bits in length. Further IP, TCP, and UDP header layout details can be found in Because most popular services are registe...