> ## Documentation Index > Fetch the complete documentation index at: https://help.freakhosting.com/llms.txt > Use this file to discover all available pages before exploring further. # How to Check Bandwidth Usage on Linux (vnStat and iftop) > Check bandwidth usage on Linux: vnstat -d and vnstat -m show daily and monthly traffic, sudo iftop shows live connections, ip -s link shows counters. To check bandwidth usage on Linux, install vnStat and run `vnstat -d` for daily or `vnstat -m` for monthly traffic per interface; it records in the background once installed. For what is using bandwidth right now, run `sudo iftop -i eth0`, which lists the busiest connections. `ip -s link show eth0` shows total bytes since boot without installing anything. | Difficulty | Time | Works on | Needs | | - | - | - | - | | Beginner | 10 minutes | Ubuntu 22.04/24.04, Debian 12/13, AlmaLinux/Rocky 9/10 | sudo access; EPEL on AlmaLinux/Rocky | ## Before you start * **Bandwidth** is how fast data moves (Mbit/s). **Traffic** is how much data moved in total (GB or TB). Received data is **rx** (inbound), sent data is **tx** (outbound). * On a VPS, the panel also shows monthly traffic for your server: see [VPS traffic and bandwidth](https://help.freakhosting.com/portals/vps-panel/understanding-vps-traffic-and-bandwidth.md). The numbers inside the server can differ slightly from the panel, because they're measured at a different point. * Find your interface name with `ip -br link` (for example `eth0`, `ens3`). Commands use `sudo`; as root, leave it out. ## Which tool should I use? | Question | Tool | | - | - | | How much traffic per day or month? | `vnstat` | | Which IP or connection is using bandwidth now? | `iftop` | | What's the current speed in and out? | `nload` or `vnstat -l` | | Total since boot, no install | `ip -s link` | ## How to see daily and monthly traffic with vnStat **1. Install vnStat** > [tab] Ubuntu / Debian > > ```bash theme={null} > sudo apt update > sudo apt install vnstat > ``` > > The `vnstat` service is enabled and started during installation. > [tab] AlmaLinux / Rocky > > vnStat is in the EPEL repository: > > ```bash theme={null} > sudo dnf install epel-release > sudo dnf install vnstat > sudo systemctl enable --now vnstat > ``` **2. Wait for the first data** The background service (`vnstatd`) adds every interface it finds and saves data every few minutes. Right after installing you'll see "No data" until the first save. ```bash theme={null} systemctl status vnstat ``` **3. Show the traffic** ```bash theme={null} vnstat # summary: today, this month vnstat -d # per day (last 30 days) vnstat -m # per month (last 12 months) vnstat -h # per hour vnstat -i eth0 -m # one interface only ``` ```text theme={null} eth0 / monthly month rx | tx | total | avg. rate ------------------------+-------------+-------------+--------------- 2026-10 312.45 GiB | 1.08 TiB | 1.39 TiB | 4.47 Mbit/s 2026-11 21.30 GiB | 80.12 GiB | 101.42 GiB | 2.21 Mbit/s ------------------------+-------------+-------------+--------------- estimated 166.02 GiB | 624.40 GiB | 790.42 GiB | ``` vnStat only knows about traffic from the moment it was installed. Use `vnstat -l` for a live view of the current rate, and `vnstat -t` for the top traffic days. ## How to see which connections use bandwidth with iftop > [tab] Ubuntu / Debian > > ```bash theme={null} > sudo apt install iftop > ``` > [tab] AlmaLinux / Rocky > > ```bash theme={null} > sudo dnf install epel-release > sudo dnf install iftop > ``` ```bash theme={null} sudo iftop -i eth0 -n -P ``` `-n` shows IP addresses instead of names (faster), `-P` shows ports. Each line is a connection between your server (`=>` sent, `<=` received) and a remote address, with the average rate over 2, 10 and 40 seconds. Press **q** to quit. For a one-off text report, for example to paste into a ticket: ```bash theme={null} sudo iftop -i eth0 -n -P -t -s 10 ``` This prints the top connections after 10 seconds and exits. To find which program owns a busy connection, take the port from iftop and look it up: ```bash theme={null} sudo ss -tunp | grep ':443' ``` ## How to see the current speed with nload ```bash theme={null} sudo apt install nload # Ubuntu / Debian sudo dnf install nload # AlmaLinux / Rocky, needs EPEL nload eth0 ``` nload shows incoming and outgoing speed as two graphs with current, average, minimum, maximum and total. Press **q** to quit. ## How to check traffic without installing anything ```bash theme={null} ip -s -h link show eth0 ``` ```text theme={null} RX: bytes packets errors dropped missed mcast 252M 57.0k 0 6 0 0 TX: bytes packets errors dropped carrier collsns 37.5M 54.4k 0 0 0 0 ``` These counters start at zero when the server boots. Rising **errors** or **dropped** values can point to a network problem. > [!WARNING] > > Sudden, large outbound traffic you can't explain may mean a compromised server sending spam or attack traffic. Check with `iftop` which addresses it goes to, and see [what to do if your Linux server is hacked](https://help.freakhosting.com/portals/other/what-to-do-if-your-linux-server-is-hacked.md). ## Frequently asked questions ### Why does vnStat show "No data"? The service hasn't saved its first sample yet, or it isn't running. Wait a few minutes and check `systemctl status vnstat`. If the interface is missing, add it with `sudo vnstat -i eth0 --add`. ### Why are vnStat's numbers different from my VPS panel? They're measured in different places and may use different units (vnStat uses GiB/TiB by default, base 1024) and different month boundaries. Use the panel for your plan's allowance. ### How do I see bandwidth per process? `iftop` works per connection, not per program. Match its ports to programs with `ss -tunp`. Tools such as `nethogs` show traffic per process directly. ### Does vnStat slow down the server? No noticeable amount. It reads the kernel's interface counters at intervals rather than capturing packets. ## Related guides > [card] [VPS and dedicated server guides](https://help.freakhosting.com/portals/other/vps-and-dedicated-server-guides.md) > > Every guide in this section. > [card] [VPS traffic and bandwidth](https://help.freakhosting.com/portals/vps-panel/understanding-vps-traffic-and-bandwidth.md) > > Traffic history in the panel. > [card] [Test speed with iperf3](https://help.freakhosting.com/portals/other/how-to-test-network-speed-with-iperf3.md) > > Measure maximum throughput. > [card] [Monitor resources with htop](https://help.freakhosting.com/portals/other/how-to-monitor-server-resources-with-htop.md) > > CPU, memory and processes. > [card] [Set up Netdata](https://help.freakhosting.com/portals/other/how-to-set-up-netdata-monitoring.md) > > Dashboards for network and more. *** > [!NOTE] > > **Checked against the official [vnStat manual](https://humdi.net/vnstat/man/vnstat.html) and [usage guide](https://github.com/vergoh/vnstat/wiki/Usage-%23-Command-line-basics)** and the Fedora/EPEL package listings for [vnStat](https://packages.fedoraproject.org/pkgs/vnstat/vnstat/), [iftop](https://packages.fedoraproject.org/pkgs/iftop/iftop/) and [nload](https://packages.fedoraproject.org/pkgs/nload/nload/) on 4 November 2026; commands tested on Ubuntu 24.04 LTS (vnStat 2.12, iftop 1.0pre4, nload 0.7.4). Commands can differ on other distributions or releases. > [!NOTE] > > ### Need Extra Help? > > If you encounter any issues, our support team is ready to assist: > > * **Live Chat:** Quick assistance via our website. > * **Support Ticket:** [Open a Ticket](https://freakhosting.com/clientarea/submitticket.php) > * **Discord:** [Join our Community](https://discord.gg/freakhosting) > * **Email:** [support@freakhosting.com](mailto:support@freakhosting.com) > [!TIP] > > ### Save on Your Hosting > > Ready to upgrade your hosting? Use code **KB20** at checkout for **20% off** your first order! *** **Last Updated:** November 2026 This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.