udp

Build your own DNS Resolver. ...

Build your own Echo server. Implement a UDP or TCP based Echo server that echoes back to the client whatever is sent to it.. ...

Build your a HTTP(S) Load Tester that can be used to simulate a load on a website or HTTP(S) based API. ...

Build your own Memcached server. Implement the TCP based Memcached protocol and build a Memcached server. ...

Build a network modelling tool that can load in a network description and some traffic data, then model the traffic flowing over the network to determine the utilisation of each link within the network. ...

An NTP client helps keep your local machine / server’s time in sync with other machines and perhaps authoratitive clocks. ...

Build your own real-time chat server and client. ...

Socat (SOcket CAT) is a command-line utility that establishes two bidirectional byte streams and transfers data between them. It’s a more versatile version of netcat. ...

Build your own Traceroute tool. ...