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How to Use ShowAllPorts to Audit Open PortsAuditing open ports is a fundamental part of network security and systems administration. Open ports can reveal services, misconfigurations, and potential attack surfaces. This article explains how to use ShowAllPorts — a conceptual tool (or script) that lists all ports and associated services on a host — to perform a thorough open-port audit. It covers prerequisites, installation and usage patterns, interpreting results, integrating ShowAllPorts into workflows, and follow-up remediation steps.
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What ShowAllPorts does (at a glance)
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ShowAllPorts enumerates TCP and UDP ports on a system, reports which are open/listening, maps them to owning processes and services, and optionally shows remote connections. It’s useful for quick inventories, troubleshooting, and security checks.
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Key outputs you should expect:
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- List of listening TCP and UDP ports
- Process ID (PID) and process name owning each port
- Local address and port, remote endpoints (when applicable)
- Protocol (TCP/UDP) and state (LISTEN, ESTABLISHED, etc.)
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Prerequisites and safety
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- Administrative (root/Administrator) privileges are usually required to view all ports and process mappings.
- Run ShowAllPorts on a trusted host or in a controlled environment. Avoid scanning networks you don’t own or have permission to test.
- Ensure your system has required runtime components (e.g., Python, .NET, or other runtimes) if ShowAllPorts is implemented as a script or binary.
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Installing ShowAllPorts
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ShowAllPorts can be distributed as:
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- A cross-platform script (e.g., Python, PowerShell)
- A native binary for Windows, Linux, macOS
- A package via a repo or package manager
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Example installation approaches:
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For a Python-based ShowAllPorts:
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- Ensure Python 3.8+ is installed.
- Install dependencies: pip install psutil
- Place showallports.py in /usr/local/bin and mark executable.
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For a PowerShell implementation:
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- Save ShowAllPorts.ps1 and run from an elevated PowerShell prompt.
- Consider setting the execution policy appropriately (e.g., RemoteSigned) only if you trust the script.
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Basic usage patterns
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Quick local audit (default):
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- Command: showallports
- Output: summary table of listening ports, protocols, PIDs, process names.
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Verbose mode with connections:
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- Command: showallports –verbose
- Output: includes remote endpoints and connection timestamps.
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Filter by protocol, port range, or PID:
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- Command examples:
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- showallports –protocol tcp
- showallports –port 80
- showallports –range 1-1024
- showallports –pid 1234
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- Command examples:
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Output to machine-readable formats:
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- Export to CSV: showallports –output report.csv
- Export to JSON: showallports –output report.json
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Remote auditing (agent or remote command):
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- Use SSH or remote management tools to run ShowAllPorts on remote hosts.
- Example: ssh admin@host “showallports –output -”
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Interpreting ShowAllPorts output
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A typical row might contain: protocol, local address:port, state, PID, process name, remote endpoint.
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Listening ports:
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- Local-only binds (127.0.0.1 or ::1) indicate services restricted to the local machine.
- 0.0.0.0 or :: binds mean the service accepts connections from any interface — higher exposure.
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Process and PID:
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- Verify whether the owning process is expected. Unrecognized or unsigned binaries warrant investigation.
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Established connections:
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- Check remote IPs for unusual or repeated connections. Geolocation or threat intelligence can help classify suspicious hosts.
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UDP ports:
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- UDP is connectionless; “listening” simply means the socket is open. Validate the service using packet capture if uncertain.
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Common audit checks and rules of thumb
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- Prioritize ports open to the internet (0.0.0.0 / ::). Confirm whether each service should be externally reachable.
- Look for common dangerous services exposed (RDP 3389, SMB 445, MySQL 3306, SSH 22) and confirm access controls.
- Confirm version and patch level of services listening on network ports.
- Compare current outputs against a baseline inventory to spot unexpected changes.
- Use Least Privilege: services should bind to specific interfaces where possible and run with minimal privileges.
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Integrating ShowAllPorts into security workflows
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- Scheduled inventory: run nightly and store JSON/CSV outputs in a central repository for trend analysis.
- Alerting: detect newly opened high-risk ports and trigger investigation tickets.
- CI/CD: include a ShowAllPorts check in build/release stages for container images or VMs to ensure only intended services are listening.
- Incident response: snapshot ShowAllPorts output early in an investigation to preserve evidence of network exposure.
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Example report snippet (CSV)
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CSV output simplifies automated parsing and long-term storage.
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protocol,local_address,local_port,state,pid,process_name,remote_address,remote_port tcp,0.0.0.0,22,LISTEN,1024,sshd,, tcp,127.0.0.1,3306,LISTEN,2048,mysqld,, udp,0.0.0.0,123,LISTEN,4096,ntpd,,
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Troubleshooting common issues
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- Missing PIDs or process names:
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- Ensure you ran the tool with elevated privileges.
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- False positives/ghost sockets:
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- A process may have recently closed; re-run or check kernel socket tables (e.g., ss, netstat).
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- Performance concerns on large hosts:
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- Use filtered scans (by range/protocol) and avoid overly verbose logging in tight loops.
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Remediation steps after audit
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- Close unnecessary services or reconfigure them to bind to loopback or specific interfaces.
- Apply firewall rules to restrict access by IP, protocol, or port.
- Update and patch services with known vulnerabilities.
- Replace insecure protocols with secure alternatives (e.g., disable telnet, use SSH with keys).
- If a suspicious process is found, isolate the host, collect forensic evidence, and follow incident response procedures.
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Automation example (Linux cron + JSON)
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- Create a script that runs ShowAllPorts and stores timestamped JSON:
\n#!/bin/bash /usr/local/bin/showallports --output /var/log/showallports/$(date +%F_%T).json\n
- Add to cron:
\n0 2 * * * /path/to/script.sh\n
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Final checklist for a port audit with ShowAllPorts
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- Run as admin/root to capture full mappings.
- Export results to JSON/CSV for storage and comparison.
- Flag all listening ports bound to 0.0.0.0/:: for review.
- Validate owning processes and patch levels.
- Apply firewall and configuration changes as needed and re-run to confirm.
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If you want, I can produce a ready-to-run ShowAllPorts script for Linux (Python) or PowerShell for Windows.
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