.: Nessus :.
The “Nessus” Project aims to provide to the internet community a free, powerful, up-to-date and easy to use remote security scanner for Linux, BSD, Solaris, and other flavors of Unix.
.: Ethereal :.
Ethereal is a free network protocol analyzer for Unix and Windows. Ethereal has several powerful features, including a rich display filter language and the ability to view the reconstructed stream of a TCP session.
.: Snort :.
Snort is an open source network intrusion detection system, capable of performing real-time traffic analysis and packet logging on IP networks.
.: Netcat :.
Netcat has been dubbed the network swiss army knife. It is a simple Unix utility which reads and writes data across network connections, using TCP or UDP protocol.
.: TCPdump :.
TCPdump is the most used network sniffer/analyzer for UNIX. TCPTrace analyzes the dump file format generated by TCPdump and other applications.
.: Hping :.
Hping is a command-line oriented TCP/IP packet assembler/analyzer, kind of like the “ping” program (but with a lot of extensions).
.: DNSiff :.
DNSiff is a collection of tools for network auditing and penetration testing. dsniff, filesnarf, mailsnarf, msgsnarf, urlsnarf, and webspy passively monitor a network for interesting data (passwords, e-mail, files, etc.).
.: GFI LANguard :.
GFI LANguard Network Security Scanner (N.S.S.) automatically scans your entire network, IP by IP, and plays the devil’s advocate alerting you to security vulnerabilities.
.: Ettercap :.
Ettercap is a multipurpose sniffer/interceptor/logger for switched LAN. 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 2500 potentially dangerous files/CGIs, versions on over 375 servers, and version specific problems on over 230 servers.
.: John the Ripper :.
John the Ripper is a fast password cracker, currently available for many flavors of Unix.
.: OpenSSH :.
OpenSSH is a FREE version of the SSH protocol suite of network connectivity tools, which encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other network-level attacks.
.: TripWire :.
Tripwire is a tool that can be used for data and program integrity assurance.
.: Kismet :.
Kismet is an 802.11 wireless network sniffer – this is different from a normal network sniffer (such as Ethereal or tcpdump) because it separates and identifies different wireless networks in the area.
.: NetFilter :.
NetFilter and iptables are the framework inside the Linux 2.4.x kernel which enables packet filtering, network address translation (NAT) and other packetmangling.
.: IP Filter :.
IP Filter is a software package that can be used to provide network address translation (NAT) or firewall services.
.: pf :.
OpenBSD Packet Filter
.: fport :.
fport identifys all open TCP/IP and UDP ports and maps them to the owning application.
.: SAINT :.
SAINT network vulnerability assessment scanner detects vulnerabilities in your network’s security before they can be exploited.
.: OpenPGP :.
OpenPGP is a non-proprietary protocol for encrypting email using public key cryptography. It is based on PGP as originally developed by Phil Zimmermann.
for more detail : http://sectools.org/
