Linux Network Bandwidth and Connection Testing

Network issues should be categorized into three types of checks: process occupancy, end-to-end throughput, and external network connectivity. This page uses nethogs, iperf3, and curl to identify problems respectively.

View process bandwidth

bashsudo apt-get update
sudo apt-get install -y nethogs
sudo nethogs

The interface will display the real-time upload and download speeds by process. Exit by q.

Test the throughput between two machines

Install iperf3 on both machines first:

bashsudo apt-get install -y iperf3

Server execution:

bashiperf3 -s

Client execution:

bashiperf3 -c <SERVER_IP> -P 4

Verification and Debugging

If the system has not installed curl, execute first:

bashsudo apt-get install -y curl

bashcurl -I --connect-timeout 10 https://github.com
ip route

iperf3 indicates the local network transmission capacity between two machines. curl checks the connection and response of a specified website. nethogs shows the bandwidth used by various processes on the local machine. These three types of results cannot be replaced by each other.

If the domain access fails but the IP works, check the DNS configuration. If iperf3 cannot connect, verify the server port and firewall rules. If only a single process uses all the bandwidth, go back to nethogs to identify the process and then adjust the concurrency level.