{{tag>Linux Réseau}} # Réseau Linux tc (Traffic Control) Introduction to Network Emulation with tc (Traffic Control) The tc command is part of the iproute package Source : https://bencane.com/simulating-network-latency-for-testing-in-linux-environments-29daad98efcc tc (Traffic Control) is a powerful Linux command used to control the kernel's network scheduler. It interfaces with a component known as netem (Network Emulator), which provides functionalities for emulating network conditions like latency, packet loss, and more. This tool is crucial for replicating real-world network scenarios, such as a WAN, within a controlled test environment. Determine Current Latency: Use the ping command to measure the current latency to a remote server. ~~~bash ping google.com ~~~ Calculate Additional Latency: Subtract the average current latency from your desired latency. Desired Latency - Current Latency = Additional Latency Apply the Latency using tc : Use the `tc` command to add the calculated delay to the network interface. ~~~bash tc qdisc add dev eth0 root netem delay 97ms ~~~ Verify the Rule : Use the `tc -s` command to ensure the delay has been correctly added. ~~~bash tc -s qdisc ~~~ Removing the Latency Rule ~~~bash tc qdisc del dev eth0 root netem ~~~