Explain the difference between TCP and UDP in the context of network communications. Highlight the key differences in terms of reliability, connection state, speed, and typical use cases in a cloud environment.

Explain the differences between Layer 2 (Data Link Layer) and Layer 4 (Transport Layer) in the OSI model. Discuss the key functions and protocols associated with each layer, including how the TCP stack fits into the OSI model.

Explain the process of DNS resolution. Describe how a domain name is resolved to an IP address, including the role of different DNS servers and caching mechanisms.

Explain what a Content Delivery Network (CDN) is and how it works.

Describe how you would design a scalable system like Hotstar to handle millions of concurrent users.

Explain the functionality and features of AWS Route 53 as a managed DNS service, including its integration with other AWS services.

Describe the sequence of events that occur from the moment a user enters a URL in the browser to the loading of the web page, including DNS resolution, TCP/IP connections, and HTTP/HTTPS protocols.

What strategies and technologies can be implemented to protect a network or application from Distributed Denial of Service (DDoS) attacks?

What are the differences between stateless and stateful architectures, and how do they impact system design?

Explain key TCP/IP concepts that are crucial for maintaining and troubleshooting a network. Focus on concepts such as IP addressing, subnetting, TCP vs. UDP, and the role of common protocols like HTTP, SSH, and DNS in network communications.

Discuss the process and significance of handling a Neighbor Discovery Protocol (NDP) request in IPv6 networks, particularly focusing on how it facilitates address resolution and the detection of other devices on the same network.

What are the methods to determine the IP address of the Baseboard Management Controller (BMC) on a server, ensuring network security and access controls are adequately considered?

What is the size of an Ethernet (MAC) address in terms of bits?

How is an IPv6 address represented and stored in a DNS system? Explain the record type used for IPv6 addresses.

Explain the process and implications of ARP spoofing in a network. How can it be mitigated?

Discuss the performance benefits of DNS using UDP over TCP for query resolution. What are the circumstances under which DNS might use TCP instead?

How can you implement a traceroute routine using ICMP and TCP, and what are the specific details and steps involved in creating this network diagnostic tool?

How would you design a read-intensive API that efficiently handles high volumes of read requests, leveraging cloud technologies and caching mechanisms?

What are the key differences between Telnet and SSH protocols in terms of security, use cases, and functionality?

How does HTTP function across all its levels in a network?

How would you approach designing low-level TCP servers, high-level HTTP API servers, and implementing an LRU (Least Recently Used) cache, considering the requirements for scalability, performance, and reliability?

Considering the need for secure communication over public networks, what are the best practices for distributing and protecting private keys to ensure confidentiality and integrity?

How can we optimize DNS and routing protocols to ensure scalability and performance in a cloud-native environment?

You are tasked with detecting and resolving various issues on an Ubuntu server. This includes identifying and fixing high CPU usage, troubleshooting web server issues, installing necessary packages, setting up a cron job for automated tasks, and writing a Python script to query an API. Describe in detail how you would approach and solve each of these tasks, including the commands and scripts you would use.

Describe how you would design and run a live production system to ensure zero downtime during deployments. Include strategies for high availability, rolling and blue-green deployments, handling distributed systems problems (like consistency and fault tolerance), and monitoring and alerting.

You are asked to identify potential causes of user latency problems and how to troubleshoot at all levels of the infrastructure. Describe the steps you would take to diagnose and resolve these latency issues, including client-side issues, network issues, server-side issues, database issues, external dependencies, and monitoring.

How did you use tcpdump? Explain the basic usage and provide examples of how to capture and analyze network traffic.

How can you configure a Linux system to route traffic destined for a specific subnet through a different gateway, while keeping this routing rule isolated from the system's main routing table? Provide the commands necessary to create a custom routing table and add a route to this table that directs traffic for the subnet 192.168.2.0/24 to pass through the gateway at 192.168.1.2 via the eth0 network interface.

You need to verify the MAC address associated with an IP address on your local network. Which command would you use to check the ARP cache and possibly refresh it if the address is not found?

Design a global video streaming service similar to Netflix or YouTube, focusing on scalability, reliability, and low latency. Consider the following:

• How would you architect the system to support millions of concurrent users globally?
• What strategies would you employ for content delivery and network efficiency?
• Discuss how you would handle metadata storage, search functionality, and user personalization at scale.

Design a scalable real-time messaging system like WhatsApp or Telegram that can support high-volume, low-latency messaging across the globe. Address the following points:

• Describe the system architecture needed to ensure message delivery with minimal delay.
• How would you design the data model to store conversations, ensure data consistency, and manage user presence status?
• Explain the trade-offs between consistency, availability, and partition tolerance (CAP theorem) in your design.

You are tasked by a Cloud Provider to create a CDN Product similar to Cloudflare. Design the architecture for the CDN service, focusing on content caching, load balancing, and global content delivery.

Design a distributed file storage system similar to Google Drive or Dropbox, capable of storing and retrieving large amounts of data across a distributed network. Consider the following aspects:

You have 10,000 servers and need to send a file of size 1 MB to each server, starting from a laptop with only 1 MB bandwidth between each server. Describe a solution to achieve the shortest possible time for this file distribution, using a tree structure and logarithmic time complexity.

How would you design the infrastructure for a retail web application? Explain how a web server, a database, firewalls, and other components would connect together.

How would you implement a caching proxy server? Describe the architecture, key components, and the steps involved in building it.

Given a fleet of 10,000 bots tasked with scraping a website without detection, how do we ensure each URL is accessed only once and distribute the workload across all nodes without revealing the operation to the site owners or implicating the bot machines?

Describe techniques you'd use scale up a system of servers for millions of users?

What steps are needed to configure a static IP address on a Windows machine and verify that it's configured correctly for network communication?

What types of DNS records are commonly used in network configuration and management?

You are tasked with designing a secure database system for Yahoo's Paranoids team, focusing on a Linux environment hosted on AWS. The system should ensure data integrity and protection against cyber threats. Additionally, propose a machine learning approach to detect and mitigate potential security breaches. Describe your approach, the technologies you would use, and the steps involved in the implementation.

How can you optimize database queries on SQL Server to reduce load times in a web application hosted on IIS, considering networking constraints within your DevOps environment?

How can we effectively integrate Azure cloud services such as Event Hub, Azure Kubernetes Service (AKS), networking, and managed databases to optimize our application's workflow for scalability and reliability?

What are the key benefits of implementing API Management solutions in a cloud architecture, and under what circumstances should it be utilized?

How would you design a connectivity architecture for a multinational company to ensure efficient and secure communication between its global offices?

How can we effectively migrate customers to new solutions utilizing Virtual Networks (Vnets), Virtual Machines (VMs), and Infrastructure as a Service (IaaS) while ensuring seamless operations and minimal disruption? What are the best practices for configuring ports and security measures in this context?

Given a dataset containing customer transaction records in a CSV format, describe how you would create a data quality dashboard to track key metrics like missing values, duplicate entries, and data type mismatches. Specify the tools and technologies you would use.