Welcome to Network 99 — your ultimate collection of 99 essential tips and tricks for network pros using the best open source software. Each tip includes a tool name, a brief description, and an official download link to help you get started quickly.
1. Wireshark
Wireshark is a powerful open source network protocol analyzer that captures live packet data from your network interfaces. It allows you to inspect network traffic at a very granular level, helping diagnose connectivity problems, security issues, or protocol bugs. It supports hundreds of protocols and offers a rich graphical user interface with filtering capabilities. Beginners and experts alike use Wireshark to visualize complex network interactions easily. Its deep packet inspection is invaluable for troubleshooting complicated network issues.
Download: https://www.wireshark.org/download.html
2. Nmap
Nmap (Network Mapper) is a widely used open source utility for network discovery and security auditing. It allows you to scan IP addresses and ports, discovering hosts and services on a network. Nmap helps identify vulnerable devices, open ports, and active services, essential for penetration testing and network inventory. It supports scripting for advanced tasks and works across platforms. With its versatility and powerful scanning options, Nmap is a must-have for any network professional.
Download: https://nmap.org/download.html
3. Ansible
Ansible is a simple, agentless automation tool used for IT orchestration and configuration management. It allows network engineers to automate repetitive tasks such as device configuration, patch management, and deployment using human-readable YAML playbooks. With built-in modules for network devices, Ansible supports a wide variety of vendors, making multi-vendor automation straightforward. Its push-based architecture requires no additional software on the managed devices. By automating complex workflows, Ansible improves efficiency, reduces errors, and enables consistent network configurations.
Download: https://docs.ansible.com/ansible/latest/installation_guide/intro_installation.html
4. OpenVPN
OpenVPN is an open source VPN solution that creates secure point-to-point or site-to-site connections. It uses SSL/TLS encryption to protect data transmitted over public networks, allowing remote users and offices to access internal networks safely. OpenVPN is highly configurable, supporting various authentication methods and network topologies. It’s compatible with many platforms and devices, making it a popular choice for securing remote access. The software provides strong encryption with excellent performance, ensuring your network data remains confidential and secure.
Download: https://openvpn.net/community-downloads/
5. tcpdump
tcpdump is a command-line packet analyzer for Unix-like systems. It captures network packets in real time, allowing admins to inspect the contents of network traffic. With powerful filtering expressions, tcpdump lets you focus on specific hosts, protocols, or ports, making troubleshooting precise and efficient. Despite its simplicity, tcpdump provides detailed information on packet headers and payloads, helping identify network problems or malicious activities. It is widely used by network engineers for quick diagnostics in environments where GUI tools aren’t available.
Download: https://www.tcpdump.org/#latest-release
6. Nagios Core
Nagios Core is a flexible open source monitoring system for servers, switches, applications, and services. It continuously checks the health of network resources, alerting admins instantly to failures or anomalies. With extensive plugin support, Nagios can monitor nearly any device or service. Its web interface provides real-time status and historical logs, assisting in proactive network management. Nagios helps maintain network uptime by detecting problems early, reducing downtime, and improving overall reliability. Its modular design allows customization to fit specific monitoring needs.
Download: https://www.nagios.org/downloads/nagios-core/
7. fail2ban
fail2ban is a security utility that scans log files to detect suspicious activity, such as repeated failed login attempts, and automatically bans offending IP addresses. Primarily used to protect SSH and other network services, fail2ban blocks brute force attacks by modifying firewall rules dynamically. It’s highly configurable, allowing admins to define filters and ban durations. This lightweight tool adds an essential layer of defense to servers, reducing the risk of unauthorized access and improving overall network security without manual intervention.
Download: https://www.fail2ban.org/wiki/index.php/Main_Page
8. Zabbix
Zabbix is an enterprise-grade monitoring platform that tracks the availability and performance of network devices, servers, and applications. It offers agent-based and agentless monitoring with customizable alerts, dashboards, and reporting. Zabbix supports many protocols, including SNMP, IPMI, and JMX, providing broad device compatibility. Its scalability allows monitoring of small setups to large, distributed environments. The intuitive web UI and powerful data visualization make Zabbix ideal for maintaining network health and diagnosing issues before they impact users.
Download: https://www.zabbix.com/download
9. Open vSwitch
Open vSwitch is an open source multilayer virtual switch designed for network automation and virtualization. It supports standard management interfaces and protocols, including OpenFlow, making it suitable for software-defined networking (SDN). Open vSwitch allows dynamic network topology changes and advanced packet processing in virtualized environments. Its compatibility with popular hypervisors like KVM and Xen enables complex virtual network configurations. Open vSwitch is widely used in cloud infrastructure to improve network efficiency, security, and flexibility.
Download: https://www.openvswitch.org/download/
10. Cacti
Cacti is a web-based network monitoring tool that collects and displays bandwidth and resource usage data using RRDtool. It provides customizable graphs for visualizing network traffic, CPU load, and memory utilization over time. Cacti’s auto-discovery feature simplifies network device additions, while its user-friendly interface enables non-experts to monitor network health easily. Ideal for tracking trends and spotting bottlenecks, Cacti helps maintain optimal network performance and capacity planning. It integrates well with other monitoring solutions, enhancing overall network visibility.
Download: https://www.cacti.net/download_cacti.php
11. LibreNMS
LibreNMS is an open source network monitoring system that supports a wide range of network hardware and operating systems. It provides auto-discovery of network devices and customizable alerting based on thresholds. With its intuitive web interface, LibreNMS offers real-time monitoring and reporting. It supports SNMP, IPv6, and multi-tenant setups. Its modular design allows users to extend functionality with plugins and integrates easily with third-party tools.
Download: https://www.librenms.org/download/
12. Netdata
Netdata is a real-time health monitoring and performance troubleshooting tool for networks, servers, and applications. It delivers high-resolution metrics and beautiful visualizations through a web dashboard. Netdata detects anomalies and unusual behaviors automatically with minimal configuration. Its distributed architecture supports monitoring multiple hosts in a single interface. Lightweight and open source, Netdata provides instant insights to help maintain network and system performance.
Download: https://www.netdata.cloud/install/
13. Elasticsearch
Elasticsearch is a powerful, open source search and analytics engine, widely used for logging, metrics, and network data analysis. It stores and indexes massive amounts of data for fast querying. Combined with Logstash and Kibana, it forms the ELK stack, a popular solution for network monitoring and troubleshooting through logs visualization. Elasticsearch is highly scalable and supports complex queries to detect network anomalies and security threats.
Download: https://www.elastic.co/downloads/elasticsearch
14. pfSense
pfSense is a free, open source firewall and router software based on FreeBSD. It offers advanced network security features such as stateful firewalling, VPN, traffic shaping, and load balancing. pfSense is highly customizable and comes with a user-friendly web interface. It is widely deployed in enterprise and home networks for robust perimeter defense and secure remote access.
Download: https://www.pfsense.org/download/
15. Suricata
Suricata is an open source intrusion detection system (IDS) and intrusion prevention system (IPS) designed for high-performance network security monitoring. It analyzes network traffic in real-time to detect suspicious activities, malware, and attacks using signature and anomaly-based detection. Suricata supports multi-threading and hardware acceleration for fast packet processing. It integrates well with other monitoring tools to provide comprehensive network security.
Download: https://suricata.io/download/
16. Nagstamon
Nagstamon is a status monitor that integrates with various monitoring systems like Nagios, Icinga, and Zabbix. It sits in your system tray and provides a quick view of network and system health, alerting you immediately to issues. Nagstamon offers customizable notifications and supports multiple monitoring instances, helping network admins keep an eye on infrastructure status effortlessly.
Download: https://nagstamon.ifw-dresden.de/
17. OpenSSH
OpenSSH is a suite of secure networking utilities based on the SSH protocol, providing encrypted communication for remote login, file transfer, and command execution. It replaces insecure protocols like Telnet and FTP with strong cryptography, safeguarding network traffic from eavesdropping and man-in-the-middle attacks. OpenSSH is essential for secure network management and administration.
Download: https://www.openssh.com/portable.html
18. RANCID
RANCID (Really Awesome New Cisco config Differ) is a network management tool that automatically collects and archives device configurations. It tracks changes over time and can alert admins to unauthorized or unexpected modifications. RANCID supports multiple device vendors and integrates well with version control systems, improving network configuration management and compliance.
Download: https://www.shrubbery.net/rancid/
19. Nagios Plugins
Nagios Plugins is a collection of community-developed scripts and binaries that extend Nagios Core's monitoring capabilities. These plugins check services, network devices, databases, and more, allowing customized monitoring tailored to your network environment. Regular updates keep the plugin set compatible and feature-rich.
Download: https://www.nagios.org/downloads/nagios-core-addons/
20. Etcd
Etcd is a distributed, reliable key-value store used to manage configuration data for distributed systems and networks. It supports leader election and distributed coordination, making it ideal for dynamic service discovery and network orchestration in cloud-native environments. Etcd ensures consistent and highly available configuration management.
Download: https://etcd.io/docs/v3.5/install/
21. OpenNMS
OpenNMS is a scalable, open source network management platform designed for fault, performance, and traffic monitoring. It provides automated discovery, event management, and customizable reports. OpenNMS supports a wide range of devices and protocols, suitable for large enterprises seeking comprehensive network visibility.
Download: https://www.opennms.org/en/install/
22. Iperf3
Iperf3 is a versatile tool for active network bandwidth measurement and performance testing. It can create TCP, UDP, and SCTP data streams and measure throughput between hosts, useful for diagnosing network speed bottlenecks and quality of service issues.
Download: https://iperf.fr/iperf-download.php
23. GNS3
GNS3 is a graphical network simulator that enables network professionals to design, configure, and test complex network topologies in a virtual environment. It supports real Cisco IOS images and other vendor OSes, making it invaluable for learning, testing, and troubleshooting.
Download: https://www.gns3.com/software/download
24. Netdata Cloud
Netdata Cloud is the SaaS extension of Netdata that allows centralized monitoring of multiple Netdata agents deployed across various hosts and locations. It provides aggregated metrics, team collaboration features, and alerting in a scalable, easy-to-use cloud interface.
Download: https://www.netdata.cloud/
25. Cilium
Cilium is an open source networking and security project that provides networking, security, and observability for cloud-native environments using eBPF technology. It offers advanced network policies and load balancing for Kubernetes clusters, enhancing network security and performance.
Download: https://cilium.io/download/
26. Prometheus
Prometheus is an open source systems monitoring and alerting toolkit, widely adopted for monitoring networks and services. It collects and stores metrics as time series data, supports flexible queries, and integrates with visualization tools like Grafana.
Download: https://prometheus.io/download/
27. Grafana
Grafana is an open source analytics and visualization platform that integrates with multiple data sources, including Prometheus and Elasticsearch. It allows users to create dashboards that visualize network metrics, logs, and alerts, facilitating network performance analysis.
Download: https://grafana.com/grafana/download
28. Open Daylight
Open Daylight is an open source platform for software-defined networking (SDN) that supports network programmability through standard protocols. It enables centralized network management and automation for complex networks and cloud infrastructures.
Download: https://www.opendaylight.org/downloads
29. VyOS
VyOS is an open source network operating system based on Linux, providing advanced routing, firewall, and VPN capabilities. It runs on physical or virtual hardware and is used for routers, firewalls, and VPN gateways.
Download: https://vyos.io/download/
30. ntopng
ntopng is a high-speed network traffic monitoring tool that provides real-time visibility into network usage. It identifies top talkers, traffic flows, and protocols, helping diagnose congestion and potential security threats.
Download: https://www.ntop.org/products/traffic-analysis/ntop/
31. ZMap
ZMap is an open source network scanner that allows rapid Internet-wide network surveys. It is designed for speed and scalability, useful for researchers and network operators to study the global Internet.
Download: https://zmap.io/download.html
32. Cuckoo Sandbox
Cuckoo Sandbox is an open source automated malware analysis system that analyzes suspicious files and URLs in a controlled environment. It helps network security teams detect and understand malware behavior.
Download: https://cuckoosandbox.org/download/
33. OpenVAS
OpenVAS (Open Vulnerability Assessment System) is a full-featured vulnerability scanner and vulnerability management tool. It scans networks and systems for security weaknesses and provides detailed reports for remediation.
Download: https://www.openvas.org/download.html
34. Bro/Zeek
Zeek (formerly Bro) is a powerful open source network security monitor that analyzes network traffic to detect intrusions, policy violations, and suspicious activities. It offers detailed logs and scripting for customized detection.
Download: https://zeek.org/download/
35. LibreSSL
LibreSSL is a fork of OpenSSL focused on security, code quality, and modern standards. It provides cryptographic libraries used in secure network communications and is a drop-in replacement for OpenSSL in many systems.
Download: https://www.libressl.org/
36. CIFS Utils
CIFS Utils provides tools for mounting and managing SMB/CIFS shares on Linux systems. It helps network admins integrate Windows shares into Linux environments for file sharing and collaboration.
Download: https://linux.die.net/man/8/mount.cifs
37. Fping
Fping is a ping-like program that uses ICMP echo requests to quickly check the reachability of multiple hosts in parallel. It is useful for network discovery and monitoring the availability of large numbers of devices.
Download: https://fping.org/download/
38. IPTables
IPTables is a command-line firewall utility built into Linux kernels, used for configuring rules to filter and manipulate network traffic. It supports NAT, filtering, and packet mangling, critical for securing Linux-based networks.
Download: https://netfilter.org/projects/iptables/index.html
39. OpenStack Neutron
OpenStack Neutron is the networking component of OpenStack, providing network connectivity as a service for cloud environments. It supports network automation, VLANs, VXLANs, and security groups.
Download: https://docs.openstack.org/neutron/latest/install/
40. Tc (Traffic Control)
Tc is a Linux utility used to configure and control network traffic control settings, including bandwidth limiting, prioritization, and shaping. It's essential for managing network QoS and optimizing performance.
Download: https://man7.org/linux/man-pages/man8/tc.8.html
41. MRTG
Multi Router Traffic Grapher (MRTG) is a tool for monitoring the traffic load on network links. It generates graphs showing traffic flow trends over time, useful for capacity planning and spotting anomalies.
Download: https://oss.oetiker.ch/mrtg/
42. OpenSSH
OpenSSH is a suite of secure networking utilities providing encrypted communication sessions over a computer network using the SSH protocol. It is essential for secure remote administration and file transfers.
Download: https://www.openssh.com/portable.html
43. Wireshark
Wireshark is the world’s most popular open source network protocol analyzer. It lets you capture and interactively browse traffic running on a computer network. You can inspect hundreds of protocols in real-time and analyze captured data offline. Wireshark’s powerful filtering capabilities help troubleshoot complex network issues. It’s widely used by network engineers for packet-level analysis, security auditing, and troubleshooting. Cross-platform support and a large community make Wireshark essential for deep network inspection.
Download: https://www.wireshark.org/download.html
44. OpenVPN
OpenVPN is a robust open source VPN solution offering secure point-to-point or site-to-site connections. It uses SSL/TLS for key exchange and supports multiple authentication methods. OpenVPN can traverse firewalls and NATs, making it versatile for remote access and private networking. It’s highly configurable with community and enterprise editions available. OpenVPN ensures strong encryption, data integrity, and reliable connectivity, making it ideal for secure network communications.
Download: https://openvpn.net/community-downloads/
45. Ansible
Ansible is an open source IT automation tool that simplifies network configuration management. With easy-to-read YAML playbooks, Ansible automates device configuration, deployment, and orchestration across your network infrastructure. It supports many network device vendors and integrates with monitoring tools. Agentless architecture and idempotency ensure safe and scalable network automation. Ansible reduces manual errors and boosts operational efficiency in complex environments.
Download: https://www.ansible.com/resources/get-started
46. tcpdump
tcpdump is a powerful command-line packet analyzer that allows network administrators to capture and display TCP/IP and other packets transmitted over the network. It is useful for troubleshooting and protocol analysis. Its filtering options enable precise capture sessions. Lightweight and available on most Unix-like systems, tcpdump is essential for on-the-fly network traffic diagnostics and debugging.
Download: https://www.tcpdump.org/
47. Nmap
Nmap (Network Mapper) is a versatile open source tool for network discovery and security auditing. It scans hosts and services, detects operating systems, and can identify open ports and vulnerabilities. Its scripting engine allows customization for advanced scanning and automation. Nmap is invaluable for network inventory, managing service upgrade schedules, and monitoring host or service uptime.
Download: https://nmap.org/download.html
48. Zabbix
Zabbix is a mature open source monitoring solution for networks, servers, cloud services, and applications. It provides real-time monitoring with configurable alerts, data visualization, and performance trending. Zabbix supports auto-discovery and extensive customization through scripts and templates. Its scalable architecture suits both small and enterprise networks.
Download: https://www.zabbix.com/download
49. Nagios Core
Nagios Core is an open source IT infrastructure monitoring system that monitors hosts, services, and network devices. It sends alerts for failures and recoveries and supports extensive plugin architecture to extend monitoring capabilities. Nagios is widely used for proactive network health management and incident response.
Download: https://www.nagios.org/downloads/nagios-core/
50. Open vSwitch
Open vSwitch is an open source multilayer virtual switch designed to automate network management and support standard management interfaces and protocols. It is commonly used in virtualized server environments to provide advanced networking features like VLAN tagging, traffic shaping, and security policies.
Download: https://www.openvswitch.org/download/
51. Elastic Stack (ELK)
The Elastic Stack (Elasticsearch, Logstash, Kibana) is an open source platform for searching, analyzing, and visualizing network logs and metrics. Elasticsearch stores and indexes data, Logstash collects and processes logs, and Kibana provides powerful dashboards. Together, they offer real-time network monitoring and troubleshooting capabilities.
Download: https://www.elastic.co/downloads/
52. Netcat
Netcat is a simple Unix utility for reading and writing data across network connections using TCP or UDP. It is known as the “Swiss Army knife” of networking due to its versatility, allowing port scanning, banner grabbing, file transfers, and debugging.
Download: https://nc110.sourceforge.io/
53. EtherApe
EtherApe is a graphical network monitor for Unix modeled after etherman. It shows network activity graphically, representing nodes and links with size and color indicating traffic volume and type. It helps visualize traffic flows and detect network bottlenecks intuitively.
Download: https://etherape.sourceforge.io/
54. Netdisco
Netdisco is a web-based network management tool providing network device discovery and inventory management. It leverages SNMP to map network topology, making it easier for administrators to manage switches, routers, and endpoints.
Download: https://netdisco.org/download
55. Cacti
Cacti is a complete network graphing solution designed to harness the power of RRDTool’s data logging and graphing. It provides an intuitive web interface for creating graphs of network traffic, CPU load, and other metrics over time.
Download: https://www.cacti.net/download_cacti.php
56. OpenNTPD
OpenNTPD is an open source implementation of the Network Time Protocol (NTP) designed for simplicity and security. It synchronizes system clocks in a network environment, essential for time-sensitive applications and logs correlation.
Download: https://www.openntpd.org/
57. SmokePing
SmokePing is a latency monitoring tool that tracks network performance over time with detailed graphs showing ping latency and packet loss. It helps detect intermittent network issues and performance degradation.
Download: https://oss.oetiker.ch/smokeping/download.en.html
58. MTR (My Traceroute)
MTR combines the functionality of traceroute and ping in a single tool, showing the path packets take to a host and measuring latency and packet loss at each hop. It’s invaluable for diagnosing network route issues.
Download: https://github.com/traviscross/mtr/releases
59. OpenBGPd
OpenBGPd is an open source implementation of the Border Gateway Protocol (BGP) used to exchange routing information across the internet and private networks. It allows administrators to build flexible and secure routing configurations.
Download: https://www.openbgpd.org/download.html
60. ntopng
ntopng is a network traffic probe that shows network usage, flows, and statistics in real-time. It helps monitor bandwidth consumption and detect suspicious traffic.
Download: https://www.ntop.org/products/traffic-analysis/ntop/
61. tcpflow
tcpflow is a tool that captures data transmitted as part of TCP connections and stores it in files for detailed analysis. It helps reconstruct sessions for troubleshooting and forensic analysis.
Download: https://github.com/simsong/tcpflow
62. Ndiff
Ndiff compares results from Nmap scans and highlights differences, making it easier to track network changes and detect new hosts or services.
Download: https://nmap.org/ndiff/
63. Netstat
Netstat is a command-line tool displaying active network connections, routing tables, and interface statistics. It’s essential for network troubleshooting and performance tuning.
Download: Usually pre-installed on most OSes.
64. Tcpick
Tcpick is a TCP packet sniffer and analyzer that tracks TCP connections, providing detailed session info and data logging for network debugging.
Download: https://github.com/npad/tcpick
65. OpenSSL
OpenSSL is a robust open source cryptographic toolkit implementing SSL and TLS protocols. It is used widely to secure network communications and manage digital certificates.
Download: https://www.openssl.org/source/
66. Fail2Ban
Fail2Ban scans log files for suspicious activity and bans IPs that show malicious signs, such as multiple failed login attempts. It helps secure network services from brute force attacks.
Download: https://www.fail2ban.org/wiki/index.php/Downloads
67. IPERF
IPERF measures maximum TCP and UDP bandwidth performance between hosts. It’s essential for network capacity testing and performance benchmarking.
Download: https://iperf.fr/iperf-download.php
68. Moloch
Moloch is an open source large scale full packet capture and indexing system. It allows fast packet search and detailed network forensics analysis.
Download: https://molo.ch/download.html
69. Netwatch
Netwatch is a lightweight network monitoring tool that checks the availability of hosts and services and executes custom actions on status changes.
Download: https://github.com/tony2001/netwatch
70. tshark
Tshark is the terminal-based version of Wireshark, allowing packet capture and analysis through the command line for scripting and automation.
Download: https://www.wireshark.org/download.html
71. Bandwhich
Bandwhich is a CLI utility to show current network bandwidth usage by process, connection, and remote IP/hostname. It helps quickly identify bandwidth hogs.
Download: https://github.com/imsnif/bandwhich
72. Squid
Squid is a caching and forwarding HTTP proxy that improves web performance by caching frequently accessed content and controlling user access.
Download: http://www.squid-cache.org/Download/
3. LibreNMS
LibreNMS is a community-driven network monitoring system offering auto-discovery, alerting, and customizable dashboards. It supports a broad range of devices via SNMP and can integrate with other tools like Grafana. LibreNMS is easy to set up and scale for growing networks, providing real-time insights to maintain network health and troubleshoot issues.
Download: https://www.librenms.org/
74. OpenSSH
OpenSSH is a secure shell protocol suite for encrypted communication and secure remote login. It replaces insecure protocols like Telnet and FTP, ensuring confidentiality and integrity of network traffic. OpenSSH includes tools for key management, tunneling, and secure file transfers.
Download: https://www.openssh.com/
75. Nagios Plugins
Nagios Plugins extend Nagios Core monitoring with thousands of checks for servers, network devices, applications, and protocols. These plugins provide critical data for proactive alerting and detailed performance metrics.
Download: https://nagios-plugins.org/download/
76. OpenDaylight
OpenDaylight is a modular open source SDN (Software-Defined Networking) controller platform. It enables network programmability and automation to optimize and secure network infrastructure, supporting multiple southbound protocols and applications.
Download: https://www.opendaylight.org/downloads
77. NetHogs
NetHogs is a small network monitoring tool that groups bandwidth by process, showing per-application network usage in real-time. It helps identify which apps consume bandwidth.
Download: https://github.com/raboof/nethogs
78. Suricata
Suricata is a high-performance network IDS, IPS, and security monitoring engine. It analyzes network traffic, detects threats, and logs suspicious activity using signature-based and anomaly-based detection methods.
Download: https://suricata.io/download/
79. Iperf3
Iperf3 is the updated version of Iperf, a tool for active measurements of the maximum achievable bandwidth on IP networks. It supports tuning, IPv6, and multiple parallel streams.
Download: https://software.es.net/iperf/
80. OpenNMS
OpenNMS is an enterprise-grade network management platform for fault, performance, and traffic monitoring. It offers scalable, automated discovery, and powerful data collection features.
Download: https://www.opennms.org/download/
81. LibreSSL
LibreSSL is a modern, open source SSL/TLS implementation forked from OpenSSL, focusing on security, simplicity, and code cleanliness. It’s used for securing network communications.
Download: https://www.libressl.org/
82. ClamAV
ClamAV is an open source antivirus engine for detecting trojans, viruses, malware, and other malicious threats on networks and endpoints. It integrates with mail servers to scan attachments.
Download: https://www.clamav.net/downloads
83. OpenWRT
OpenWRT is a Linux-based open source firmware for routers, enabling extensive customization, advanced routing, firewall rules, and package installation for network devices.
Download: https://openwrt.org/downloads
84. Snort
Snort is an open source network intrusion detection and prevention system capable of real-time traffic analysis and packet logging. It uses a rules-based language to detect suspicious activities.
Download: https://www.snort.org/downloads
85. IPTables
IPTables is a user-space utility program for configuring Linux kernel firewall implemented within the Netfilter project. It provides packet filtering, NAT, and logging for network security.
Download: Usually pre-installed on Linux systems.
86. Bro (Zeek)
Zeek, formerly known as Bro, is a powerful open source network analysis framework focusing on security monitoring, traffic logging, and anomaly detection.
Download: https://zeek.org/download/
87. Open Source Router OS - VyOS
VyOS is a community-driven open source router and firewall platform based on Linux. It offers enterprise routing features for VPN, firewall, and network management.
Download: https://vyos.io/download/
88. RANCID
RANCID (Really Awesome New Cisco confIg Differ) automates network device configuration management by retrieving device configs and tracking changes via version control.
Download: https://www.shrubbery.net/rancid/
89. Traceroute
Traceroute is a diagnostic tool that tracks the path packets take to a network host, measuring transit delays of packets across the internet.
Download: Usually pre-installed on most OSes.
90. WiFi Analyzer (LinSSID)
LinSSID is a graphical tool for scanning wireless networks on Linux. It helps visualize Wi-Fi channels, signal strengths, and interference for better network planning.
Download: https://sourceforge.net/projects/linssid/
91. NetXMS
NetXMS is an enterprise-grade network and infrastructure monitoring system providing automatic discovery, alerting, and performance analysis with customizable dashboards.
Download: https://netxms.org/download
92. OpenStack Networking (Neutron)
OpenStack Neutron provides “networking as a service” between interface devices managed by other OpenStack services, enabling flexible and scalable cloud networking.
Download: https://docs.openstack.org/neutron/latest/
93. Zenmap
Zenmap is the official GUI for Nmap, making network scanning accessible for beginners and professionals through easy-to-use graphical interfaces.
Download: https://nmap.org/zenmap/
94. Netcat-traditional
A version of Netcat optimized for traditional Unix systems, useful for simple data transfers, port listening, and debugging network issues.
Download: https://nc110.sourceforge.io/
95. OpenStack Horizon
OpenStack Horizon is a web-based dashboard for managing OpenStack services including networking, instances, and storage with user-friendly graphical tools.
Download: https://docs.openstack.org/horizon/latest/
96. PacketFence
PacketFence is an open source network access control (NAC) system that provides endpoint registration, remediation, and guest management to secure networks.
Download: https://packetfence.org/download/
97. FreeRADIUS
FreeRADIUS is the most popular open source RADIUS server, used for authentication, authorization, and accounting in network access control.
Download: https://wiki.freeradius.org/guide/Download
98. OpenVPN Access Server
The OpenVPN Access Server provides an easy-to-use VPN server with web-based admin and client configuration management, built on the open source OpenVPN.
Download: https://openvpn.net/vpn-server-resources/
99. tcpdump
tcpdump is a powerful command-line packet analyzer. It captures network packets for analysis, essential for debugging and network forensics.
Download: https://www.tcpdump.org/