The network attacks can be categorized into two types, namely, external attacks and internal attacks. The description for the same is defined below:


These sorts of attacks attempt to bring about clogging situation in the system, denial of service (DoS), and promoting incorrectly routing data and so forth. The representation of external attack is shown in figure.

Outer attacks keep the system from typical communication and delivering extra overhead to the system. Outer attacks can arrange into two classes.

  • Passive Attacks

MANETs are more powerless to passive attacks. A passive attack does not adjust the information transmitted inside of the system. Yet, it incorporates the unapproved “listening” to the system activity or collects information from it. Passive attacker does not disturb the operation of a routing protocol but rather endeavors to find the essential data from routed traffic.

  • Active Attacks

These are the attacks in which message is sent within the streams of data packets. These attacks provide authorization to malicious users. E.g DDOS, Clogging etc.


Internal attacks are specifically prompts the attacks on nodes shows in system and connections interface between them. Figure is showing the representation of internal attack.

  • Wormhole attack

It is one of the attacks that occurred in MANET. It is the extreme attack in MANET. In tis attack node A send the RREQ message to node B. Now between them node X and node Y are malicious nodes. So path becomes long as now data packet will go from A-X-Y-B so delay will occur in transmission process. This is the wormhole attack in the network and is shown in figure. 

If proper routing be utilized then we can prevent from wormhole attack

  • Black Hole Attack

In black hole attack, a pernicious hub sends fake directing information, engaging that it has a most ideal route and additionally causes other great hubs to route other packets too through the malevolent one. In AODV, the assailant could coordinate a fake RREP (counting a fake destination grouping number that is manufactured to be equivalent or higher than the one contained in the RREQ) to the source hub, affirming that it has a satisfactorily new course to the objective hub. This causes the essential hub to pick the course that goes through the assailant. Thus, all activity will be diverted through the aggressor, and additionally therefore, the assailant can sick utilize or dispose of the movement.

  • Flooding Attack

The goal of the flooding assault is to deplete the system resources, for example, data transfer capacity and to devour a hub’s properties, for instance computational alongside battery control or to disturb the routing operation to bring about extreme debasement in framework execution. In AODV method, a pernicious hub could coordinate countless in a brief period to a destination hub that does not exist in the framework. The majority of the hub battery power, alongside system data transmission will be utilized and could prompt foreswearing of-administration.

  • Link Spoofing Attack

In this attack, a malignant hub promotes fake connections with non-neighbors to disturb routing forms.Fig. Example of Link Spoofing Attack on OLSR


For example, in the OLSR methodology, an assailant can advance a fake association by method for an objective’s two-bounce neighbors as shown in figure. This is the reason in light of which the objective hub to pick the noxious hub to be the previously stated MPR. By method for a MPR hub, a malignant hub could without much of stretch then control information or routing activity, for case, altering or else decreasing the directing movement or performing different sorts of DoS assaults.

  • Link withholding Attack

In this assault, a vindictive hub overlooks the prerequisite to promote the connection of particular hubs or a gathering of hubs, which can bring about connection misfortune to these particular hubs. This class of assault is generally serious in the OLSR convention.

  • Sink hole Attack

In a sinkhole attack, the intruder’s aim is to lure all the traffic from a particular area through a compromised node, to launch an attack. The compromised node tries to attract all the traffic from neighbor nodes based on the routing metrics used in the routing protocol. Sinkhole attack is one among the routing attacks. Sinkhole attacks are difficult to counter because the routing information supplied by a node in a wireless sensor network is difficult to verify.

Table is showing the difference among black hole, worm hole and Sybil attack. The comparison has been made on the basis of attacking type, categories, packet loose, battery power and delay.Table Difference between Black Hole, Warm Hole Attack and Sybil Attack

Differences Sybil Attack Warm Hole Black hole
Attacking type It is an attack wherein a reputation system is subverted by forging identities in peer-to-peer networks. In a typical wormhole attack, the attacker receives packets at one point in the network. When all the messages are redirected to a specific node, it is defined as black hole attack.
Categories In- Direct Collaborative Attack Direct Collaborative Attack Direct Collaborative Attack
Packet loose 30% 40% 50%
Battery Power Moderate Moderate High
Delay 20% 20% 20%


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