Tracing byzantine faults in ad hoc networks
The Ad hoc On-Demand Distance Vector (AODV) protocol
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| The Ad hoc On-Demand Distance Vector (AODV) protocol
On-demand routing protocols are most appropriate for ad hoc networks due to their inherently dynamic nature. The Ad hoc On Demand Distance Vector protocol [15] is a commonly used routing protocol in which routes are only maintained as long as they remain active. This limits the overhead required to support route discovery, as every change to the network topology does not need to be broadcast to the entire network unless it affects an active route. In the AODV protocol, the route setup is done in two phases. First, the network is flooded by the source node s with a request for a path to the destination node d. The body of the request bodys contains a source node identifier ids, a destination node identifier idd, a request sequence number and an authenticator hKsd(bodys) where hKsd is a keyed MAC (Message Authentication Code [18]) with key Ksd which is shared by s and d. Furthermore, the request also contains the hop count to be used by the destination node. In this way, the whole network can be mapped to a graph tree whose root is the source node s [7]. Since ad hoc networks are constantly changing, the source needs to closely monitor the path in order to maintain it in the face of transmission losses due to either network failures or malicious activities. When failure occurs, the source needs to identify the faulty links in order to avoid using them in the construction of new paths. However, the problem is harder than it first appears because, not only can malicious nodes cause link failures under their control, but they can also damage other links not under their control by supplying false information to the source and destination nodes. Download 138.2 Kb. Share with your friends:
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