Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
Scapy - Scapy is a powerful interactive packet manipulation program.
Fing - Discover which devices are connected to any Wi-Fi network, map devices, detect intruders, assess...
Winsock Packet Editor - WPE Pro is a packet editor.
SoftPerfect Network Scanner - Powerful multipurpose network administration tool for Windows and macOS
packeth - packeth is GUI and CLI packet generator tool for ethernet.