Computer Networking DNS Review Questions and Answers 100% Pass

Computer Networking DNS Review Questions and Answers 100% Pass DNS Use Cases - Answers -Translates hostname to IP Address -Host/Mail Server Aliasing Load Distribution (enables load balancing by allowing multiple IP Addresses to correspond to a single domain name, DNS can direct users to different servers, or distribute traffic evenly and improve performance) Why Don't we centralize DNS - Answers -Single point of failure (If the central DNS server fails, it could bring down the entire internet's domain resolution capabilities) -Traffic Volume (A centralized DNS would struggle to handle millions of queries a day) -Distance to centralized database -Would require a lot of maintenance. DNS Hiearchy - Answers - TLD (second level, domains such as .com .org .edu) -Authoritative' (provide IP address of the requested domain) -Root (Top-level, contains information for where to find the top level domains) DNS iterative Query Process (example. Client wants the IP Address for ) - Answers 1. Query root server (client first queries a root server to find out where the .com DNS servers are located 2.Query TLD server (The client then queries the .com DNS server to get information about the DNS servers) 3. Query Authoritative Server (Client queries the DNS server to get the IP address for ) What is the importance of the Hierarchical Structure in DNS - Answers Ensures scalability and efficiency. Each level in the DNS hierarchy focuses on a specific part of the domain name which allows the system to distribute queries across the different servers. Also important for caching Root name servers - Answers They are the starting point of the DNS query process and are the last resort point that DNS servers contact when they cannot resolve a name. They are important since the DNS system would not be able to locate TLD servers without them and would break the internet. What is the role of ICANN - Answers They are responsible for managing the root DNS domain. ICANN coordinates with various organizations to maintain the root server infrastructure Local DNS name server - Answers -does not strictly belong to hierarchy each ISP has one also called "default name server" -when host makes DNS query, query is sent to its local DNS server -acts as proxy, forwards query into hierarchy Iterative Query - Answers -client sends a request to its local DNS server asking for the IP address of a domain -if the DNS server doesn't have the IP server in its cache then the DNS server responds with the next server to contact.