Blue-net

A Qt5 network connection monitor for Linux. It shows every TCP and UDP socket on the system — local and remote endpoints, ports, state — and maps each socket to the process and user that opened it, so you can see what the connection is, how it was established, and why it exists (which program created it).

Build

Requires cmake, g++, make and Qt5 development packages:

sudo apt install -y build-essential cmake qtbase5-dev
mkdir build && cd build
cmake ..
make -j$(nproc)

Run

./build/blue-net          # your own processes only
sudo ./build/blue-net     # all users' processes (recommended)

CLI listing mode (no GUI):

./build/blue-net --list

Install

sudo make install         # installs to /usr/local/bin/blue-net

Features

• Live view of all TCP / TCP6 / UDP / UDPv6 sockets from /proc/net/*
• Socket → process mapping via /proc/*/fd (PID, name, user)
• Color-coded states, protocol/state/text filters, sortable columns
• Auto-refresh with adjustable interval, F5 manual refresh
• Details dialog per connection: WHAT (endpoints, services), HOW (TCP state, direction) and WHY (process, executable, command line, reverse DNS)
• Right-click: copy rows as TSV, end the owning process (SIGTERM)