iftop
A real-time bandwidth monitor for the terminal.
iftop displays a top-style list of network connections sorted by bandwidth use. The display shows source and destination, two- or three-second moving-average throughput, and cumulative byte counts, all updating in real time. Filtering with libpcap-style expressions narrows the view to specific hosts, ports, or protocols.
Paul Warren wrote iftop in 2002 inspired by top's process display. Since then it has become a standard system-administration tool, packaged in every major Linux distribution and on macOS via Homebrew. The implementation is small and remarkably self-contained.
iftop is the quickest way to find out which hosts are saturating an interface from a remote shell — much faster than dropping into tcpdump or running a full Wireshark capture. It pairs naturally with NetHogs (which shows the same bandwidth data grouped by process) for a complete real-time picture of network activity.
Install
Debian/Ubuntu: sudo apt install iftop Fedora/RHEL: sudo dnf install iftop Arch: sudo pacman -S iftop macOS: brew install iftop
Authors
- Paul Warren (creator)