knockd is a port-knock daemon. It listens to all traffic on an ethernet or PPP interface, looking for special "knock" sequences of port-hits (UDP/TCP packets sent to a server port). This port need not be open, since knockd listens at the link-layer level.

Yggdrasil is an early-stage implementation of a fully end-to-end encrypted IPv6 network. It is lightweight, self-arranging, supported on multiple platforms and allows pretty much any IPv6-capable application to communicate securely with other Yggdrasil nodes. Yggdrasil does not require you to have IPv6 Internet connectivity - it also works over IPv4.

This package contains a variety of tools for dealing with network configuration, troubleshooting, or servers. Utilities included are:

arping

Ping hosts using ARP.

clockdiff

Compute time difference between network hosts using ICMP TSTAMP messages.

ninfod

Daemon that responds to IPv6 Node Information Queries.

ping

Use ICMP ECHO messages to measure round-trip delays and packet loss across network paths.

rarpd

Answer RARP requests from clients.

rdisc

Populate network routing tables with information from the ICMP router discovery protocol.

tftpd

Trivial file transfer protocol server.

tracepath

Trace network path to an IPv4 or IPv6 address and discover MTU along the way.

FRRouting (FRR) is an IP routing protocol suite which includes protocol daemons for BGP, IS-IS, LDP, OSPF, PIM, and RIP.

Squid is a caching proxy for the Web supporting HTTP, HTTPS, FTP, and more. It reduces bandwidth and improves response times by caching and reusing frequently-requested web pages.

Open vSwitch is a multilayer virtual switch. It is designed to enable massive network automation through programmatic extension, while still supporting standard management interfaces and protocols (e.g. NetFlow, sFlow, IPFIX, RSPAN, CLI, LACP, 802.1ag).

The Simple Network Management Protocol (SNMP) is a widely used protocol for monitoring the health and welfare of network equipment (e.g. routers), computer equipment and even devices like UPSs. Net-SNMP is a suite of applications used to implement SNMP v1, SNMP v2c and SNMP v3 using both IPv4 and IPv6.

Axel tries to accelerate the download process by using multiple connections per file, and can also balance the load between different servers. It tries to be as light as possible, so it might be useful on byte-critical systems. It supports HTTP, HTTPS, FTP and FTPS protocols.

librdkafka is a C library implementation of the Apache Kafka protocol, containing both Producer and Consumer support.

Pixiewps implements the pixie-dust attack to brute force the Wi-Fi Protected Setup (WPS) PIN by exploiting the low or non-existing entropy of some access points.

NetHogs is a small 'net top' tool for Linux. Instead of breaking the traffic down per protocol or per subnet, like most tools do, it groups bandwidth by process.

NetHogs does not rely on a special kernel module to be loaded. If there's suddenly a lot of network traffic, you can fire up NetHogs and immediately see which PID is causing this. This makes it easy to identify programs that have gone wild and are suddenly taking up your bandwidth.

bmon is a monitoring and debugging tool to capture networking-related statistics and prepare them visually in a human-friendly way. It features various output methods including an interactive curses user interface and a programmable text output for scripting.

ENet's purpose is to provide a relatively thin, simple and robust network communication layer on top of UDP. The primary feature it provides is optional reliable, in-order delivery of packets. ENet omits certain higher level networking features such as authentication, server discovery, encryption, or other similar tasks that are particularly application specific so that the library remains flexible, portable, and easily embeddable.

The ngtcp2 project is an effort to implement the RFC9000 (IETF) QUIC protocol.

Proxychains-ng is a preloader which hooks calls to sockets in dynamically linked programs and redirects them through one or more SOCKS or HTTP proxies.

uBridge is a simple program to create user-land bridges between various technologies. Currently, bridging between UDP tunnels, Ethernet and TAP interfaces is supported. Packet capture is also supported.

The IP class allows a comfortable parsing and handling for most notations in use for IPv4 and IPv6 addresses and networks.

Libproxy handles the details of HTTP/HTTPS proxy configuration for applications across all scenarios. Applications using libproxy only have to specify which proxy to use.

NNG project is a rewrite of the scalability protocols library known as libnanomsg, and adds significant new capabilities, while retaining compatibility with the original. It is a lightweight, broker-less library, offering a simple API to solve common recurring messaging problems, such as publish/subscribe, RPC-style request/reply, or service discovery.

iPerf is a tool to measure achievable bandwidth on IP networks. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). For each test it reports the bandwidth, loss, and other parameters.

The dhtnet is a C++ library providing abstractions for interacting with an OpenDHT distributed network.

Tool to send a magic packet to wake another host on the network. This must be enabled on the target host, usually in the BIOS.

ethtool can be used to query and change settings such as speed, auto-negotiation and checksum offload on many network devices, especially Ethernet devices.

Nload is a console application which monitors network traffic and bandwidth usage in real time. It visualizes the in- and outgoing traffic using two graphs, and provides additional info like total amount of transferred data and min/max network usage.