phpIPAM - phpipam is an open-source web IP address management application (IPAM).
Charles Proxy - HTTP proxy / HTTP monitor / Reverse Proxy
BlueCat DDI - Unify your DDI (DNS, DHCP and IPAM) solutions to make DDI data an engine for innovation and growth.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.
ManageEngine OpUtils - ManageEngine OpUtils is an IP address and Switch port management software that includes a comprehensive set of 30+ tools that helps network engineers monitor, diagnose and troubleshoot their IT resources.
Postman - The Collaboration Platform for API Development