D329 Networks and Security Applications - Set 4 - Part 1

Correct Answer: Logical addressing that supports routing between different networks

IP addresses are logical and hierarchical, allowing routers to forward traffic between networks. MAC addresses are flat and only meaningful within a local segment.

Correct Answer: 127.0.0.1

127.0.0.1 is the IPv4 loopback address, referring to the local host itself and used to test the local TCP/IP stack.

Correct Answer: The host failed to obtain an address from a DHCP server

Automatic Private IP Addressing assigns a 169.254.x.x address when no DHCP server responds, signaling a DHCP or connectivity problem.

Correct Answer: 2

A /30 has 2 host bits giving 4 addresses, minus the network and broadcast addresses, leaving 2 usable hosts. This suits point-to-point links.

Correct Answer: 255.255.0.0

A /16 prefix means the first 16 bits are the network portion, which is written as 255.255.0.0 in dotted decimal notation.

Correct Answer: To divide a network into smaller segments improving performance and security

Subnetting divides a network into smaller broadcast domains, reducing broadcast traffic, improving performance, and enabling security boundaries between segments.

Correct Answer: Storing paths a router uses to forward packets toward destinations

A routing table lists known destination networks and the next hop or interface to use, which the router consults for every forwarding decision.

Correct Answer: Static routes are manually configured; dynamic routes are learned via protocols

Static routes are entered manually and never change automatically. Dynamic routing protocols exchange information so routers adapt to topology changes.

Correct Answer: Automatically exchanging network reachability information between routers

Routing protocols like OSPF let routers advertise known networks and compute best paths, adapting automatically when links fail or topology changes.

Correct Answer: The path used when no more specific route matches

The default route is the catch-all used when no more specific entry matches the destination, typically pointing toward the internet gateway.

Correct Answer: A rule set permitting or denying traffic based on defined criteria

An ACL filters traffic by matching criteria such as source and destination address, protocol, and port, then permitting or denying matching packets.

Correct Answer: Rules are evaluated top down and the first match applies

ACLs process rules sequentially and act on the first match, so a broad permit placed before a specific deny renders the deny ineffective.

Correct Answer: Traffic not explicitly permitted is denied by default

Most ACLs end with an implicit deny, so any traffic not matching an explicit permit is dropped, implementing a default-deny security posture.

Correct Answer: Only explicitly approved traffic is permitted, reducing unknown exposure

Default-deny requires explicit authorization for each permitted flow, ensuring unanticipated or newly introduced traffic is blocked rather than silently allowed.

Correct Answer: Directing traffic arriving on a specific external port to an internal host

Port forwarding maps an external port on the router to an internal host and port, allowing selected inbound services to reach systems behind NAT.

Correct Answer: They expose internal services directly to internet-based attacks

Each forwarding rule creates a path from the internet to an internal system, expanding the attack surface. Unused rules should be removed.

Correct Answer: An intermediary that forwards requests on behalf of clients

A proxy sits between clients and destinations, forwarding requests. It can enforce policy, cache content, and hide internal client details.

Correct Answer: Fronting internal servers to handle requests from external clients

A reverse proxy receives external requests and forwards them to internal servers, providing load balancing, TLS termination, and a protective layer for backends.

Correct Answer: Distributing incoming traffic across multiple backend servers

A load balancer spreads requests across a pool of servers, improving capacity and availability by routing around failed or overloaded backends.

Correct Answer: Designing systems to remain operational despite component failures

High availability eliminates single points of failure through redundancy and automatic failover so services continue despite individual component failures.