Router Security

Route flapping is a phenomenon in computer networking where a route

$($path$)$ to a particular destination repeatedly alternates between

available and unavailable states. The attacker can exploit flapping to

induce rapid and continuous changes in the reachability status of a

route, causing disruption and detriment to a router's operation. Flapping

leads to increased frequency in routing information exchange, resulting

in heightened CPU utilization and control plane congestion in a router.

Consider a scenario in which the attacker selectively targets specific

routers downstream by causing a route to flap only once. Explain why

this action by the attacker may occasionally lead to a significant number

of updates being processed by a router several hops downstream,

resembling the impact of multiple route flaps. This issue could naturally

arise due to unreliable links, but it is frequently exploited by attackers

to disrupt router operation in real$-$world scenarios.

Hint: Specific network topologies facilitate the attacker in achieving its

objectives.

Kindly provide the references accordingly as well.