How does TCP differ from UDP regarding delivery reliability?
TCP is connection-oriented and guarantees delivery, whereas UDP is connectionless and provides best-effort delivery.
Which specific TCP vulnerability involves overwhelming a target by leaving connections in a half-open state?
SYN Flood attack.
Why is UDP frequently used in reflection and amplification Denial of Service (DoS) attacks?
It is connectionless and lacks a handshake mechanism, making it easy to spoof source addresses.
What is the primary security risk associated with using standard HTTP for web communication?
Data is sent in plaintext, making it susceptible to eavesdropping and Man-in-the-Middle (MITM) attacks.
Which protocol is responsible for mapping a known IP address to an unknown MAC address on a local network?
Address Resolution Protocol (ARP).
Explain the goal of an ARP Poisoning attack.
An attacker sends false ARP messages to associate their MAC address with the IP address of a legitimate network device.
Why do security administrators often block ICMP messages at the network perimeter?
ICMP can be exploited for network reconnaissance to map internal topology or to launch DoS attacks.
Which security feature is used to prevent unauthorized or rogue DHCP servers from assigning IP addresses?
DHCP Snooping.
Define DNS Poisoning (also known as DNS Spoofing).
An attack where false IP address mappings are injected into a DNS resolver’s cache to redirect users to malicious sites.
The technique of exfiltrating data by hiding it within DNS queries is known as _____.
DNS Tunneling
What is the total bit length of an $IPv4$ address?
An $IPv4$ address is $32$ bits long.
What is the total bit length of an $IPv6$ address?
An $IPv6$ address is $128$ bits long.
Which security protocol is built-in and mandatory for the $IPv6$ standard?
$IPsec$.
At which layer of the OSI model do MAC addresses operate?
Layer 2 (Data Link Layer).
What is the primary security benefit of network segmentation using VLANs?
It contains threats by limiting an attacker’s ability to move laterally across the network.
In CIDR notation (e.g., $/24$), what does the number following the slash represent?
The number of bits used for the network portion of the address.
What is the primary function of Network Address Translation (NAT)?
It translates private internal IP addresses into a single public IP address for internet access.
Why is NAT considered a ‘layer of obscurity’ rather than a true security control?
It hides internal network topology but does not actively filter or inspect traffic for threats.
Which of the following is a reserved private $IPv4$ address range: $10.0.0.0/8$, $172.16.0.0/12$, or $192.168.0.0/16$?
All three are reserved private $IPv4$ address ranges.
What distinguishes a Public IP address from a Private IP address regarding internet routing?
Public IPs are globally routable on the internet, while Private IPs are not.
Concept: Network Security Architecture
Definition: The comprehensive plan for security device placement, configurations, and policies across the infrastructure.
Where should an organization place public-facing servers, such as web or email servers, to isolate them from the trusted internal network?
In a Demilitarized Zone (DMZ).
In a virtualized environment, what is the software layer that manages hardware resources and runs multiple Guest OSs?
The Hypervisor.
What specific security risk occurs if an attacker compromises a virtual machine and gains access to the underlying Hypervisor?
VM Escape.
