Black Hole Attack and its Counter Measures in AODV Routing Protocol
AODV-Ad hoc On-Demand Distance Vector (AODV) Routing
Other AODV nodes forward this message
message backwards
Black hole attack- black hole drops message
Black hole attack
Co-operative Black hole attack
watch dog- Mitigating routing misbehavior in mobile ad hoc networks
Watchdog method
Disadvantages-collision
Disadvantages-cheating
Pathrater
Pathrater
Pathrater and watchdog

AODV-Ad hoc On-Demand Distance Vector (AODV) Routing

In AODV, the network is silent until a connection is needed. At that point the network node that needs a connection broadcasts a request for connection. Other AODV nodes forward this message, and record the node that they heard it from, creating an explosion of temporary routes back to the needy node. When a node receives such a message and already has a route to the desired node, it sends a message backwards through a temporary route to the requesting node. The needy node then begins using the route that has the least number of hops through other nodes. Unused entries in the routing tables are recycled after a time. When a link fails, a routing error is passed back to a transmitting node, and the process repeats.