If someone attacks a linux-system, most administrator would block the ip-address of the attacker using iptables-rules. But there is another method to block the address of an attacker: nullroutes. Nullroutes are routes to nowhere
Routing to loopback
Its possible to just route traffic to the loopback interface:
route add ATTACKERS-IP gw 127.0.0.1 lo
Rejecting route
Using the route-command we can also add a reject-router:
route add -host ATTACKERS-IP reject
