IP Services Flashcards
What is a host file?
Computer file used by an OS to map hostnames to IP addresses
What does a host file serve as to allow the overriding of DNS lookup?
A simple form of local DNS resolution
How is a host file commonly used?
Testing website deployment and blocking access to unwanted sites through redirection of domain names to incorrect or loopback IP addresses
Does the system check the external DNS server first?
No, it checks the host file before querying the external DNS server
Why are time synchronization protocols essential within the network?
Provide consistent and accurate time across all devices
Time synchronization is crucial for coordinating activities and ensuring the integrity of time-sensitive operations.
Where does time synchronization protocols play a critical role?
Network operations, logging, security, and proper sequence of events in distributed systems
These areas require precise timing to function correctly and efficiently.
What is the oldest and most common time protocol?
NTP
NTP stands for Network Time Protocol, which has been widely adopted for time synchronization.
What sort of system does NTP use to minimize the impacts of variable network latency?
Hierarchical system
This system allows NTP to manage time synchronization across multiple levels of servers.
What is the extension of NTP designed to provide security and improvements?
NTS (Network Time Security)
NTS enhances NTP by adding security features to protect against various vulnerabilities.
What does NTS add to NTP?
Encryption and authentication
These features help secure the time synchronization process against tampering and unauthorized access.
What is Precision Time Protocol (PTP) used for?
Precise time synchronization within nanoseconds
PTP is often used in applications requiring high precision, such as telecommunications and financial transactions.
How does the Address (A) Record allow users to access websites using human-readable domain names instead of numerical IP addresses?
The Address (A) Record maps a domain name with the corresponding IPv4 address
This allows users to enter a domain name instead of having to remember the numerical IP address.
Which record is the most commonly used record type in DNS settings?
Address (A) Record
This record is essential for mapping domain names to IPv4 addresses.
How is the AAAA Record similar to an Address (A) Record?
Maps a domain name to an IPv6 address
This enables the use of IPv6 addresses, which are necessary due to the exhaustion of IPv4 addresses.
When is the CNAME Record used?
When multiple domain names resolve to the same IP address
This is useful for directing different domain names to the same server.
What does the CNAME Record map to?
An alias name to a canonical domain name
This allows users to use different aliases for the same server.
What are MX Records responsible for?
Specifying the mail servers for receiving email messages on behalf of a domain
This is crucial for email delivery and routing.
What do TXT Records hold for sources outside of the domain?
Text information
TXT Records can include various types of text data relevant to the domain.
How can TXT Records be used?
Verifying domain ownership and implementing email security
They can also hold SPF or DKIM data for email validation.
What are the security measures used for securing emails?
SPF and DKIM
These protocols help in authenticating the sender’s domain and protecting against email spoofing.
What does the NS Record identify?
DNS server responsible for a specific domain
It plays a critical role in DNS delegation and management.
How can NS Records be useful?
Delegating subdomains and managing multiple DNS servers
This allows for organized DNS management across different servers.
How does a PTR Record differ from an A or AAAA Record?
Maps an IP address to a domain name
This is used for reverse DNS lookups.
How are PTR Records primarily used?
Reverse DNS lookup, network troubleshooting, and security checks
They are essential for verifying the identity of servers.
What is name resolution?
Converting human-readable domain names into IP addresses
What is a recursive DNS query?
Involves a DNS server taking on the responsibility of retrieving data from other DNS servers to resolve the name fully
What are DNS zone types?
Portions of the domain name space in the DNS which are managed by a specific entity or administrator
What does a forward zone resolve?
Domain names to IP addresses
What kind of records does the forward zone contain?
A, AAAA, and MX
What does the reverse zone handle?
Maps IP addresses back to domain names
What zone type is used for reverse DNS lookup?
Reverse zone
What is the reverse zone often needed for?
Network troubleshooting and security verification
Does the Authoritative DNS zone need to query other sources?
No it has the final authority over its own records
Where has the information been obtained from with the non-authoritative zone?
From another server
What kind of data is usually sourced from the non-authoritative DNS zone?
Cached from other previous queries
What is the primary zone?
Main zone file where DNS records are stored and managed
What does the primary zone allow?
Changes to DNS records directly
What are secondary zones used for?
Fault tolerance, redundancy, and reduce loads/backup
Can you make changes to DNS records in the secondary zone?
No, they are read-only copies of the primary zone
What does the DNS Security Extension (DNSSEC) do?
Provides authentication of DNS data
What does DNSSEC use to validate DNS responses come from an authentic source?
Digital Signatures
What is one example of a DNS-based attack?
Cache poisoning
What protocols are designed to encrypt DNS queries?
DoH (DNS over HTTPS) and DoT (DNS over TLS)
What kind of attacks does DoH and DoT ensure security against?
Eavesdropping and Man-in-the-middle attacks (On-path attack)
