A ferramenta que você está procurando é dnctl
. Para citar a manpage:
plr packet-loss-rate
Packet loss rate. Argument packet-loss-rate is a floating-point number between 0 and 1, with 0 meaning no loss, 1 meaning 100% loss. The loss rate is internally repre-
sented on 31 bits.
E:
To drop random incoming IPv4 and IPv6 ICMP packets with a probability of 5%, create a pipe:
dnctl pipe 10 config plr 0.05