Computer Networks Multiple Choice Questions on “Network Attacks”.
1. The attacker using a network of compromised devices is known as _____________
a) Internet
b) Botnet
c) Telnet
d) D-net
Answer: b
Clarification: Botnet is a network of compromised devices used by the attacker without the owner’s knowledge to perform unethical activities such as spamming. The attacker usually uses the least secure devices to create the botnet.
2. Which of the following is a form of DoS attack?
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) All of the mentioned
Answer: d
Clarification: In a DoS attack, the attacker won’t let the victims access the network by using a certain method that ensures that an essential network resource is unavailable to the victim. In vulnerability attack, the attacker exploits any obvious vulnerable entity in the network to deny the victim access into the network. In bandwidth flooding, the attacker floods the victim with a huge flow of packets and uses up all the bandwidth. In connection flooding, the attacker floods the victim network with a huge number of connections, so that, no other machine can connect to it.
3. The DoS attack, in which the attacker establishes a large number of half-open or fully open TCP connections at the target host is ________
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) UDP flooding
Answer: c
Clarification: In Vulnerability attack, the attacker exploits the vulnerable control points of the network to deny access to the victims. In Bandwidth flooding, the attacker intentionally uses up all the bandwidth by flooding the victim with a deluge of packets and makes sure that the victim can’t use any bandwidth. In UDP flooding, too many UDP packets are sent by the attacker to the victim at random ports.
4. The DoS attack, in which the attacker sends deluge of packets to the targeted host is ________
a) Vulnerability attack
b) Bandwidth flooding
c) Connection flooding
d) UDP flooding
Answer: b
Clarification: In Bandwidth flooding, the attacker floods the victim machine with a deluge of packets to make sure that no bandwidth is available. The victim then cannot utilize the complete bandwidth to perform its operation.
5. Packet sniffers involve ____________
a) Active receiver
b) Passive receiver
c) Legal receiver
d) Partially-active receiver
Answer: b
Clarification: The function of packet sniffers is to just silently receive the packets flowing in the channel. If they inject any packets into the channel, they might alert the other users about the intrusion.
6. Sniffers can be prevented by using _______________
a) Wired environment
b) WiFi
c) Ethernet LAN
d) Switched network
Answer: d
Clarification: Switches make sure that the packet is sent to the intended receiver and no one else, thus preventing Sniffers to perform their function. Intelligent switches are hence used preferably for the network.
7. Firewalls are often configured to block ___________
a) UDP traffic
b) TCP traffic
c) Sensitive traffic
d) Best-effort traffic
Answer: a
Clarification: UDP is more vulnerable to attacks, so firewalls are often configured to block suspicious UDP traffic.
8. In a network, If P is the only packet being transmitted and there was no earlier transmission, which of the following delays could be zero?
a) Propagation delay
b) Queuing delay
c) Transmission delay
d) Processing delay
Answer: b
Clarification: Since there is no other packet to be transmitted, there is no need for a queue. Therefore, the delay caused due to the queuing would be none i.e. 0.