A "must have" list of tools

ConEmu

ConEmu-Maximus5 aims to be handy, comprehensive, fast and reliable terminal window where you may host any console application developed either for WinAPI (cmd, powershell, far) or Unix PTY (cygwin, msys, wsl bash).

Putty

Probably the most used SSH and Telnet client for Windows. Developed originally by Simon Tatham for the Windows platform. PuTTY is open source software that is available with source code and is developed and supported by a group of volunteers.

HFS – HTTP File Server

This is the smallest (2.5 MB), full featured and ready to use in seconds, web server for Windows. As the developer says: It’s file sharing, it’s webserver, it’s open source, it’s free, it’s guaranteed to contain no malware.

3Com FTP and TFTP server

This 3Com Daemon a very popular and useful application. It contains a FTP, TFTP and Syslog server but also a TFTP client. Its simple interface allows you to switch between FTP, TFTP server or client with the click of a button.

TFTPD

Tftpd is a free, opensource IPv6 ready application which includes DHCP, TFTP, DNS, SNTP and Syslog servers as well as a TFTP client. The TFTP client and server are fully compatible with TFTP option support (tsize, blocksize and timeout), which allow the maximum performance when transferring the data.

Multicast Hammer

Multicast Hammer is an easy to use testing tool that allows a network engineer or administrator to test and validate multicast configurations on their network. The tool provides a quick and simple means of creating multicast servers that transmit unicast streams to multicast group addresses, along with the setup of multiple clients that listen to these addresses. User documentation here.

Infection Monkey

The Infection Monkey is an open source Breach and Attack Simulation (BAS) tool that assesses the resiliency of private and public cloud environments to post-breach attacks and lateral movement.

Nectus Traffic Generator, QoS Tester

This application allows network engineers to measure real network throughput, measure delays and jitter for traffic between two IPs. Application consists of Sender and Receiver. Sender sends UDP packets to IP address where Receiver is running. Receiver calculates traffic statistics such actual throughput, average delays, mean jitter and absolute mean jitter, lost and out of order packets. Nice tool to stress test a router, server or find out if there are any bottlenecks in your network. (only for Windows)