{{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.
<code bash>
ping google.com
</code>

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.
<code bash>
tc qdisc add dev eth0 root netem delay 97ms
</code>

Verify the Rule : Use the ''tc -s'' command to ensure the delay has been correctly added.
<code bash>
tc -s qdisc
</code>

Removing the Latency Rule
<code bash>
tc qdisc del dev eth0 root netem
</code>