Questions and Answers
Which component would go in box 1 of the SDN paradigm?
Controller
Which component would go in box 2 of the SDN paradigm?
Switch
Which component would go in box 3 of the SDN paradigm?
Application Layer
Which component would go in box 4 of the SDN paradigm?
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An IXP cannot offer peering without an SDX-enabled architecture.
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Traffic engineering is an example application of an SDX-enabled architecture.
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Within an SDX architecture, each AS can drop, forward, or modify its own traffic.
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An AS participant needs to coordinate 'offline' with other AS participants before advertising a path.
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What is BGP Blackholing used to safeguard against?
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Under which attack is traffic intercepted by a malicious actor and manipulated before it reaches the receiving host?
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What property of secure communication is violated when a message is intercepted, but not changed, by an unintended third party?
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Which property of secure communication is primarily compromised when an attacker successfully carries out a Denial of Service (DoS) attack?
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How can the victim AS use Prefix De-aggregation to defend against the attack?
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What method does Mitigation with Multiple Origin AS use to ensure that BGP hijacking is thwarted?
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What will AS2 do when it detects that it is under a DDoS attack?
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Which DNS censorship method discards all network traffic going to a set of specific IP addresses?
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The Great Firewall of China uses DNS poisoning to block access to certain websites. Does this process lead to overblocking?
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Which DNS censorship method involves a proxy examining and discarding objectionable content?
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Which TCP flag does the Great Firewall of China use to block connections?
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What does the measurement machine detect if the IP ID is initially 6 and the final IP ID is 8?
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What is a key feature of streaming stored video in multimedia applications?
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Which of the following statements best describes the concept of 'effective packet loss' in the context of VoIP applications?
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Which quality-of-service metric for VoIP is impacted by the time it takes to encode the audio?
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Which quality-of-service metric for VoIP is improved by using an appropriately sized buffer at the end system?
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The TCP receive buffer and the media player's client buffer are the same thing.
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Which method increases bandwidth consumption for managing packet loss with VoIP?
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Which method guesses the lost packet in VoIP?
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Which is the correct method to calculate the buffer-filling rate in a video buffer?
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Where is the bottleneck that causes packet loss and increased latency?
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An end-user directly interacts with the authoritative DNS server.
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Can CDN cluster selection be influenced by factors other than geographical proximity and server health?
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Which layer of the Internet stack does the DNS protocol belong to?
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Study Notes
Software-Defined Networks (SDN) Overview
- SDN decouples the control plane from the data plane, allowing centralized network management and programmable forwarding.
- Advantages include increased automation, programmability, and flexibility in network configuration.
Packet Forwarding in SDN
- Rules for packet forwarding can be calculated based on network policies, traffic conditions, and application requirements.
- SDN allows dynamic adjustments to routing rules based on real-time data.
Control Plane Functions
- The control plane is responsible for path computation, network topology discovery, and resource management.
- Data collection for analytics and reporting also falls under the control plane's functions.
Components in SDN Architecture
- Box 1 can represent Host Info which provides details about devices on the network.
- Box 2 typically represents the Network Controller that manages communication between the control and data planes.
- Box 3 often refers to the Physical Infrastructure, including switches and routers.
- Box 4 could represent various Applications or APIs that interact with the SDN system.
Internet Exchange Points (IXPs)
- IXPs cannot facilitate peering without a Software-Defined Exchange (SDX) architecture, ensuring efficient data exchange.
- Traffic engineering is an application that utilizes SDX capabilities for optimized network performance.
- Autonomous Systems (AS) in an SDX can manage their own traffic by dropping, forwarding, or modifying packets as needed.
BGP Protocol Insights
- BGP (Border Gateway Protocol) is the prevalent routing protocol that can lead to management difficulties, including routing inefficiencies.
- Limitations include susceptibility to route hijacking and requiring extensive coordination among AS participants before advertising paths.
P4 Language and Model
- The P4 model is designed to provide flexibility in packet processing using a high-level programming language.
- It allows customization of data plane functions to suit various network applications.
OpenFlow Protocol
- OpenFlow is a key protocol in SDN, enabling direct communication between the control plane and the data plane.
- It facilitates dynamic updates to flow tables on switches.
Security Concerns in Networking
- BGP Blackholing is a strategy to protect against Distributed Denial of Service (DDoS) attacks.
- Traffic interception compromises data integrity while interference with legitimate communication is a security threat.
- Properties of secure communication include confidentiality, data integrity, and availability, each affected by varying types of attacks.
DNS and Censorship Techniques
- The Great Firewall of China employs DNS poisoning, which can lead to overblocking of legitimate websites.
- Different DNS censorship methods exist, including content proxies that filter based on defined criteria.
Multimedia and VoIP Applications
- Streaming video typically has a higher bit rate requirement compared to image galleries or audio players.
- Effective packet loss in VoIP refers to the perception of voice quality degradation due to missing packets.
- Quality-of-service metrics for VoIP are affected by encoding time and buffer management strategies.
Internet Architecture and DNS
- The DNS protocol is classified under the application layer of the Internet stack.
- Iterative DNS queries involve multiple servers to sequentially resolve domain names, from root to authoritative servers.
- Content Delivery Networks (CDNs) may select clusters based on factors beyond geographical proximity, including latency and user load.
Network Management Techniques
- Techniques such as buffer management can reduce packet loss and enhance media streaming quality.
- BGP blackholing as a response to DDoS attacks is coordinated between ISPs to mitigate impact on the victim AS.
Trends in Internet Topology
- The trend in Internet topology evolution indicates increasing complexity and scalability, reflecting technological advancements.
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Description
This quiz assesses your understanding of Software-Defined Networks (SDN). It covers essential concepts such as packet forwarding rules and control plane functions. Test your knowledge on the fundamental principles of SDNs and their applications in modern networking environments.
