FREE TOOLS

IP Calculator

ipcalc takes an IP address and netmask and calculates the resulting broadcast, network, Cisco wildcard mask, and host range. By giving a second netmask, you can design subnets and supernets. It is also intended to be a teaching tool and presents the subnetting results as easy-to-understand binary values.

http://www.solarwinds.com/downloads/

Misc Tools

Solar Winds Download Page: Go to bootom of page for free tools, not just free trials.
Our favorites: Response Time Viewer for Wireshark (Application Response Times) and IP Address Tracker (Scans, Tracks & Consolidates IP Address Information)

http://www.wireshark.org/

Packet analyzer for your pc.

Free software and training videos. Excellent site

http://www.putty.org/

Free Telnet/SSH Software emulator for your pc.

https://filezilla-project.org/

Free FTP Server Solution

http://www.angryip.org/

Angry IP Scanner (or simply ipscan) is an open-source and cross-platform network scanner designed to be fast and simple to use. It scans IP addresses and ports as well as has many other features. Excellent NetFlow analyzer