Cisco’s bug search tool can be clunky but it helps engineers find any documented bugs within Cisco product software (Requires CCO)

Cisco’s Command Lookup helps engineers find that elusive command in a Cisco’s product software (Requires CCO)

Wondering which Cisco software supports a certain feature, this tool will help (Requires CCO)

Cisco’s Output Interpeter helps engineers identify potential issues with Cisco products based on the show output commands (CCO Required)

Provides a resource to view significant issues within Cisco products that are non-security related

Pretty self-explanatory, provides a location to review Cisco security advisories, responses and notices

Cisco’s validated designs provide engineers with lab proven reference designs

Cisco’s WLC Analyzer, is a handy tool to check for a number of WLC issues (Requires registration and CCO login)

An opensource stateful firewall and intrusion protection application for Linux

A opensource Unix environment for Windows

GNS is an opensource Graphical Network Simulator which can be used to emulate a range of routers and firewalls, I’ve mainly used it for Cisco and Juniper labs.

An opensource Windows simple ISO creator

An opensource graphical verson of Iperf which can be used to test TCP and UDP network throughput scenarios

An opensource maintained fork of the popular Putty tool. Provide client Telnet , SSH and serial services

Kali is the rebanded Backtrack, an opensouce OS for pentration testing

An opensource tabbed, multi-protocol, remote connections manager. Can manage third-party connectors (Kitty,etc).

Ncat is a small opensource CLI application which can be used to test TCP or UDP network services

An opensource enhanced notepad editor, very handy for reading numerous coding formats

An opensource VPN software platform

An opensource NAC solution. Handy for BYOD deployments

An opensource replacment for Microsoft Project

An opensource tool that can push CLI to numerous vendor products and store device configurations

An opensource linux firewall OS

An opensource anonymity OS

An opensource web-based system adminstrator for Linux

An opensource Windows simple CD/DVD emulator

An opensource SCP/FTP/STP client

An opensource network protocol analyzer