Question: I will start by saying that I'm completely new to Linux, so bear with me please.

I saw other questions on different sites but either there was no answer, or I didn't understand it.

I'm on a Asus ROG GL502VS-GZ427T at work and Xubuntu 16.04.3 is installed. It's a fresh installed, the laptop is a few days old. In the mouse & touchpad settings, I cannot adjust mouse OR touchpad sensitivity. It does nothing. My mouse is a Razer Taipan.

It is probably a matter of drivers but I have no idea where to start looking... 

Help would but much appreciated

EDIT: I managed to change the touchpad sensitivity using `xinput --set-prop 18 "Synaptics Finger" 50 80 257`, so it works in command line.

Answer: 
The `random` module in iptables can be used to create packet loss.  

For a 10% incoming packet loss:

```
$ sudo iptables -A INPUT -m statistic --mode random --probability 0.1 -j DROP

```

Resulting in this ping result from another computer:

```
--- rpi01-wifi.smythies.com ping statistics ---
247 packets transmitted, 217 received, 12% packet loss, time 246752ms
rtt min/avg/max/mdev = 0.958/4.933/169.588/17.884 ms

```

Similarly for outgoing packets:

```
$ sudo iptables -A OUTPUT -m statistic --mode random --probability 0.1 -j DROP

```

Resulting in this ping result from another computer:

```
--- rpi01-wifi.smythies.com ping statistics ---
1006 packets transmitted, 871 received, 13% packet loss, time 305146ms
rtt min/avg/max/mdev = 0.892/7.363/476.902/35.397 ms, pipe 2

```

Combining both `INPUT` and `OUTPUT` forced packet loss, but at 0.5% probability each:

```
$ sudo iptables -A INPUT -m statistic --mode random --probability 0.005 -j DROP
$ sudo iptables -A OUTPUT -m statistic --mode random --probability 0.005 -j DROP

```

Results in:

```
--- rpi01-wifi.smythies.com ping statistics ---
1000 packets transmitted, 967 received, 3% packet loss, time 253840ms
rtt min/avg/max/mdev = 0.876/7.583/536.867/36.065 ms, pipe 3

```

See also [here](https://stackoverflow.com/questions/614795/simulate-delayed-and-dropped-packets-on-linux/1088475#1088475).
[netem](https://wiki.linuxfoundation.org/networking/netem) leverages functionality already built into Linux and userspace utilities to simulate networks and can do exactly what you're asking.

From their [homepage](https://wiki.linuxfoundation.org/networking/netem).

> 
> **Packet loss**
> 
> 
> Random packet loss is specified in the 'tc' command in percent. The
>  smallest possible non-zero value is:
> 
> 
> 232 = 0.0000000232%
> 
> 
> # tc qdisc change dev eth0 root netem loss 0.1%
> 
> 
> This causes 1/10th of a percent (i.e 1 out of 1000) packets to be
>  randomly dropped.
> 
> 
> An optional correlation may also be added. This causes the random
>  number generator to be less random and can be used to emulate packet
>  burst losses.
> 
> 
> # tc qdisc change dev eth0 root netem loss 0.3% 25%
> 
> 
> This will cause 0.3% of packets to be lost, and each successive
>  probability depends by a quarter on the last one.
> 
> 
> Probn = .25 \* Probn-1 + .75 \* Random
> 
> 
>