NB! It seems this console command is not compatible with CS2.
Command Profile

NET_FAKELOSS

CS:GO

This command will simulate packet loss on the specified percentage of packets (i.e. 50% would drop 50% of packets).

Syntax
net_fakeloss [Percentage]

Description

This command will simulate packet loss on the specified percentage of packets (i.e. 50% would drop 50% of packets).

Syntax And Arguments

net_fakeloss [Percentage]
Percentage The percentage of packets to drop (to simulate packet loss). 20 = 20%.