Que tal adicionar interface fictícia e definir a rota para essa interface?
# ip link add dummy0 type dummy
# ip link set dev dummy0 up
# ip route add 8.8.8.8/32 dev dummy0
# ping -c3 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
--- 8.8.8.8 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2015ms
Ele sempre envia pacotes para qualquer endereço (vizinho ou remoto) em dummy0
.
# tshark -i dummy0
Running as user "root" and group "root". This could be dangerous.
Capturing on 'dummy0'
1 0.000000 10.10.0.59 -> 8.8.8.8 ICMP 98 Echo (ping) request id=0x1ce0, seq=1/256, ttl=64
2 1.007348 10.10.0.59 -> 8.8.8.8 ICMP 98 Echo (ping) request id=0x1ce0, seq=2/512, ttl=64
3 2.015394 10.10.0.59 -> 8.8.8.8 ICMP 98 Echo (ping) request id=0x1ce0, seq=3/768, ttl=64