Application Layer Flashcards
What is the client server model
^ some form of network, the sever receives requests and responds to them as it offers a service
in P2P networks what can end devices function as
both a server and a client with the same communication
What is DNS
Domain Name System
What are the main components of a URL
Scheme, authority (host/domain name), path, query, and fragment.
What is the difference between hostname and an IP address
A hostname is a human-readable name (e.g., google.com), while an IP address (e.g., 8.8.8.8) is used by machines.
How can multiple hostnames be mapped to one IP address?
Through shared hosting, multiple websites can share a single IP address.
How can one hostname be mapped to multiple IP addresses?
For load balancing and redundancy, a hostname may resolve to different IP addresses.
What are the key requirements of DNS
Scalability and security
What is the DNS hierarchy?
It consists of:
Root DNS servers (.)
Top-Level Domain (TLD) servers (e.g., .com, .org, .uk)
Second-Level Domain (SLD) servers (e.g., google.com)
Third-Level Domain servers (e.g., www.google.com)
What are Root DNS servers?
The top-level DNS servers responsible for directing queries to the appropriate TLD servers.
How many root DNS server exist
There are 13 logical root servers, each with multiple physical instances.
What are Top-Level Domain (TLD) servers?
These servers handle domains under categories like organizational (.com, .org, .edu) and geographical (.uk, .us, .fr).
What is the role of a DNS resolver?
It queries DNS servers to resolve a domain name to an IP address.
What is DNS caching?
The storage of DNS query results to speed up future lookups.
What are some common DNS security threats?
Cache poisoning (inserting false data into a resolver’s cache)
Spoofing (forging DNS responses)
Man-in-the-middle attacks (intercepting DNS communication)
