tc:tldr:98664

tc: Add constant network delay to outbound packages.

$ tc qdisc add dev ${eth0} root netem delay ${delay_in_milliseconds}ms

try on your machine

This command is used to add network emulation to the specified network interface using the Traffic Control (tc) command-line utility.

Let's break down the different parts of the command:

tc: It stands for Traffic Control, a command-line utility used to configure the Linux kernel's networking stack.
qdisc: It stands for Queueing Discipline. A queueing discipline is a module within the kernel that determines how packets are queued and processed.
add: It specifies the action of adding a new queueing discipline to the network interface.
dev ${eth0}: It specifies the network interface to which the queueing discipline will be added. ${eth0} is a placeholder for the actual network interface name, typically in the format eth0, eth1, etc.
root: It specifies that the newly added queueing discipline will be the root of the hierarchy. The root queueing discipline is responsible for controlling the overall characteristics of the network traffic.
netem: It stands for Network Emulation, which is a queueing discipline that emulates various network conditions like delay, packet loss, etc.
delay ${delay_in_milliseconds}ms: It is a parameter of the netem queueing discipline, where ${delay_in_milliseconds} is a placeholder for the desired delay in milliseconds. This parameter introduces a delay in the network traffic, simulating the effect of network latency.

Therefore, the given command is used to add network emulation with a delay to a specific network interface (${eth0}), introducing a delay of ${delay_in_milliseconds} milliseconds in the network traffic passing through it.

This explanation was created by an AI. In most cases those are correct. But please always be careful and never run a command you are not sure if it is safe.

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