Real-world Internet type topologies generated using Transit-Stub model of GT-ITM topology generator are used to test our proposed scheme, where transit
domains are treated as different Internet Service Provider (ISP) networksi.e.,
Autonomous Systems (AS). For simulations, we use ISP level topology, which
contains four transit domains with each domain containing twelve transit nodes
i.e.,transit routers. All the four transit domains have two peer links at transit
nodes with adjacent transit domains. Remaining ten transit nodes are connected
to ten stub domain, one stub domain per transit node. Stub domains are used to
connect transit domains with customer domains, as each stub domain contains
a customer domain with ten legitimate client machines. So total of four hundred
legitimate client machines are used to generate background traffic. Total zombie
machines range between 10 and 100 to generate attack traffic. Transit domain
four contains the server machine to be attacked by zombiemachines [10].