Armory
Ostinato
Ostinato is an open-source network packet and traffic generator and analyzer with a friendly GUI. It aims to be "Wireshark in Reverse" and become complementary to Wireshark. It features custom packet crafting with editing of any field for several protocols: Ethernet, 802.3, LLC SNAP, VLAN (with Q-in-Q), ARP, IPv4, IPv6, ...
Observium
Observium is an auto-discovering PHP/MySQL based network monitoring system focused primarily on Cisco and Linux networks but includes support for a wide range of network hardware and operating systems. Observium has grown out of a lack of easy to use NMSes. It is intended to provide a more navigable interface ...
Netsparker
Netsparker® can find and report security issues such as SQL Injection and Cross-site Scripting (XSS) in all web applications regardless of the platform and the technology they are built on. Netsparker's unique detection and exploitation techniques allows it to be dead accurate in reporting hence it's the first and the ...
Vistumbler 
(1 rating)
A wireless network scanner for Windows Vista and Windows 7, which wraps Window's netsh utility to obtain wireless information. Also includes GPS support.
AsItHappens Network Statistic Collector
AsItHappens is a real-time network statistic collector and grapher. It collects data from devices over a network and displays them on a graph, optionally storing collected data in a database for later retrieval. Current collection types include network response, bandwidth, processor usage, memory usage, Cisco NBAR, Cisco NetFlow and arbitrary ...
Overlook - Fing
Fing is the ultimate tool for network discovery and scanning, allowing administrators to troubleshoot their network easily and at the speed of light. Once installed on a Windows, Mac or Linux computer, your home, office and corporate network are just one click away.
EveryPing
EveryPing shows you: 1. Your IP address 2. Your host name 3. The round trip ICMP delay between the EveryPing server and your firewall 4. The RFC Jitter calculated from the ICMP delay 5. A chart with the most recent 10 delay results
Likewise Software
Securely Integrate Linux, Unix, and Mac with Active Directory by allowing the machines to join the domain and users to authenticate with their domain credentials.
LanSweeper
Lansweeper is a powerful solution to make a complete software, hardware, computer inventory of your Windows network.
ManageEngine OpManager (1 rating)
OpManager supports monitoring using Syslog, SNMP, SNMP Traps, Cisco IP SLA, NetFlow, sFlow, IP-FIX, NBAR, CBQoS, TFTP/ SCP (for Network Configuration Management), WMI, Event Log (for Windows Servers) and Telnet/ SSH (for UNIX platform devices). It is a commercial network monitoring and management software (a free version also exists for ...
TheDude
This is an awesome utility for doing SNMP tracking, network usage, the works! You can underlay geographical maps to use on you WAN maps or floorplans for LAN mapping. It can track just about anything under the sun that is network connected. Best of all, it's free!
Advanced IP Address Calculator
Advanced IP Address Calculator is an easy-to-use IP subnet calculator that lets you calculate every aspect of your subnet configuration in a few mouse clicks! The calculator generates a color-coded bit map, breaking down the network, subnet, and host portion. It shows you the subnet host address range, the subnet ...
Advanced LAN Scanner
Advanced LAN Scanner is a small, easy-to-use, highly configurable network scanner for Win32. And it's VERY fast. Advanced LAN Scanner uses multithreading so you can scan more than 1000 elements per second! If used to scan ports, Advanced LAN Scanner can scan all 65536 ports in less than a minute! ...
Advanced Port Scanner
Advanced Port Scanner is a small, fast, robust and easy-to-use port scanner for Win32 platform. It uses a multithread technique, so on fast machines you can scan ports very fast. Also, it contains descriptions for common ports, and can perform scans on predefined port ranges.
Advanced IP Scanner
Advanced IP Scanner is a fast, robust and easy-to-use IP scanner for Windows. It easily lets you have various types of information about local network computers in a few seconds! Advanced IP Scanner gives you one-click access to many useful functions - remote shutdown and wake up, Radmin integration and ...
KeePass
KeePass is a free open source password manager, which helps you to manage your passwords in a secure way.
Wireshark 
(8 ratings)
Wireshark is the world's foremost network protocol analyzer, and is the de facto (and often de jure) standard across many industries and educational institutions.
netcat (2 ratings)
Netcat is a featured networking utility which reads and writes data across network connections, using the TCP/IP protocol. It is designed to be a reliable "back-end" tool that can be used directly or easily driven by other programs and scripts. At the same time, it is a feature-rich network debugging ...
Nessus
The Nessus vulnerability scanner, is the world-leader in active scanners, featuring high speed discovery, configuration auditing, asset profiling, sensitive data discovery and vulnerability analysis of your security posture. Nessus scanners can be distributed throughout an entire enterprise, inside DMZs, and across physically separate networks. When Nessus is managed with Tenable's ...
Snort
Snort is an open source network intrusion prevention and detection system utilizing a rule-driven language, which combines the benefits of signature, protocol and anomaly based inspection methods. With millions of downloads to date, Snort is the most widely deployed intrusion detection and prevention technology worldwide and has become the de ...
Metasploit Framework (2 ratings)
The Metasploit Framework is a development platform for creating security tools and exploits. The framework is used by network security professionals to perform penetration tests, system administrators to verify patch installations, product vendors to perform regression testing, and security researchers world-wide. The framework is written in the Ruby programming language ...
hping
hping is a command-line oriented TCP/IP packet assembler/analyzer. The interface is inspired to the ping(8) unix command, but hping isn't only able to send ICMP echo requests. It supports TCP, UDP, ICMP and RAW-IP protocols, has a traceroute mode, the ability to send files between a covered channel, and many ...
Kismet
Kismet is an 802.11 layer2 wireless network detector, sniffer, and intrusion detection system. Kismet will work with any wireless card which supports raw monitoring (rfmon) mode, and can sniff 802.11b, 802.11a, and 802.11g traffic. Kismet identifies networks by passively collecting packets and detecting standard named networks, detecting (and given time, ...
iperf (1 rating)
Iperf was developed by NLANR/DAST as a modern alternative for measuring maximum TCP and UDP bandwidth performance. Iperf allows the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, datagram loss.
tcpdump
A command-line packet sniffer capable of dumping varying amounts of detail per packet to stdout, in real time. Originally written for UNIX-like systems, a port for Microsoft Windows was created and named WinDump.
Cain & Abel
Cain & Abel is a password recovery tool for Microsoft Operating Systems. It allows easy recovery of various kind of passwords by sniffing the network, cracking encrypted passwords using Dictionary, Brute-Force and Cryptanalysis attacks, recording VoIP conversations, decoding scrambled passwords, recovering wireless network keys, revealing password boxes, uncovering cached passwords ...
John the Ripper
John the Ripper is a fast password cracker, currently available for many flavors of Unix (11 are officially supported, not counting different architectures), Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. Besides several crypt(3) password hash types most commonly found on various Unix flavors, ...
ettercap
Ettercap is a suite for man in the middle attacks on LAN. It features sniffing of live connections, content filtering on the fly and many other interesting tricks. It supports active and passive dissection of many protocols (even ciphered ones) and includes many feature for network and host analysis.
Nikto
Nikto is an Open Source (GPL) web server scanner which performs comprehensive tests against web servers for multiple items, including over 3500 potentially dangerous files/CGIs, versions on over 900 servers, and version specific problems on over 250 servers. Scan items and plugins are frequently updated and can be automatically updated ...
OpenSSH
OpenSSH is a FREE version of the SSH connectivity tools that technical users of the Internet rely on. Users of telnet, rlogin, and ftp may not realize that their password is transmitted across the Internet unencrypted, but it is. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection ...
