IP Services Flashcards
In what type of environments is dynamic addressing useful?
In environments with frequently changing network devices
Dynamic addressing allows devices to join and leave networks without manual configuration.
What can dynamic addressing reduce?
Configuration errors and administrative overhead
Reducing manual IP address assignment minimizes mistakes.
What is the difference between DHCP and DHCP server?
The server assigns the IP information needed, but DHCP is a network management protocol used on IP networks
DHCP stands for Dynamic Host Configuration Protocol.
What is the DHCP scope?
A defined range of IP addresses used to assign to clients
Scopes help manage the allocation of IP addresses effectively.
Why are DHCP scopes useful?
Organize and manage IP address distribution
Scopes help prevent IP address conflicts.
What is lease time for DHCP servers?
Duration for which a DHCP server grants a device the right to use a specific IP address
Lease time can be adjusted based on network needs.
What does the device do when a lease time becomes expired?
Renew current IP or get a new one
The renewal process allows continued network access.
What can lease times help manage in an IP network?
Availability of IP addresses
Effective lease time management ensures optimal usage of available IPs.
What does reservation mean with DHCP?
Specific IP address within a scope that is reserved for use by a device
Reservations ensure that critical devices always have the same IP address.
What IP does a device get when an address is reserved for a specific device?
The same IP consistently
This is important for devices that need constant connectivity.
What are some of the capabilities that DHCP options allow?
Passing configurations such as DNS and NTP
DHCP options enhance the configuration capabilities of devices.
What are DHCP relays?
Network functions that forwards DHCP requests to a DHCP server on another network
Relays help in managing DHCP across different network segments.
What are DHCP relay agents used for?
Extending the reach of DHCP servers across multiple subnets
Relay agents facilitate communication between clients and servers in different subnets.
How can devices on different subnets obtain IP addresses without a direct DHCP server?
DHCP relay
This allows centralized management of IP address allocation.
What are exclusion ranges of a DHCP scope?
Subsets not used for dynamic assignment
Exclusion ranges help to reserve IPs for specific devices.
What can exclusion range IP addresses be reserved for?
Manual assignment for devices that require a fixed IP address
This is useful for printers, servers, and other critical devices.
What is Stateless Address Autoconfiguration (SLAAC)?
Feature in IPv6 that allows devices to automatically configure its own IP address
SLAAC simplifies network configuration for devices.
Does SLAAC in IPv6 require manual configuration or DHCP?
No, a device can generate its own IPv6 based on router advertisements it receives and its own MAC address
This enables devices to self-configure without external assistance.
What capability does SLAAC provide for ease of deployment of IPv6 networks?
Plug-and-play connectivity
This feature allows devices to join networks effortlessly.
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 critical for operations that depend on time accuracy.
Where does time synchronization protocols play a critical role?
Network operations, logging, security, and proper sequence of events in distributed systems
Ensures that events are correctly ordered and logged.
What is the oldest and most common time protocol?
NTP
NTP stands for Network Time Protocol.
What sort of system does NTP use to minimize the impacts of variable network latency?
Hierarchical system
This system helps manage time distribution across different levels.
What is the extension of NTP designed to provide security and improvements?
NTS (Network Time Security)
NTS enhances NTP with additional security features.
What does NTS add to NTP?
Encryption and authentication
These features help protect time synchronization from tampering.
What is Precision Time Protocol (PTP) used for?
Precise time synchronization within nanoseconds
PTP is often used in environments requiring high accuracy, such as telecommunications.
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 enables users to type in a domain name instead of remembering a numerical IP address.
Which record is the most commonly used record type in DNS settings?
Address (A) Record
It is fundamental for domain name resolution.
How is the AAAA Record similar to an Address (A) Record?
Maps a domain name to an IPv6 address
This allows the use of longer IPv6 addresses.
When is the CNAME Record used?
When multiple domain names resolve to the same IP address
This is useful for domain aliases.
What does the CNAME Record map to?
An alias name to a canonical domain name
This helps in redirecting traffic from one domain to another.
What are MX Records responsible for?
Specifying the mail servers for receiving email messages on behalf of a domain
Essential for email routing.
What do TXT Records hold for sources outside of the domain?
Text information
This can include various types of data, including verification details.
How can TXT Records be used?
Verifying domain ownership and implementing email security
Commonly used for SPF and DKIM records.
What are the security measures used for securing emails?
SPF and DKIM
These protocols help prevent email spoofing.
What does the NS Record identify?
DNS server responsible for a specific domain
Crucial for domain delegation.
How can NS Records be useful?
Delegating subdomains and managing multiple DNS servers
This allows for better organization of DNS records.
How does a PTR Record differ from an A or AAAA Record?
Maps an IP address to a domain name
This is useful for reverse lookups.
How are PTR Records primarily used?
Reverse DNS lookup, network troubleshooting, and security checks
Important for verifying the identity of an IP address.
What is name resolution?
Converting human-readable domain names into IP addresses
Name resolution is essential for accessing websites and services on the internet.
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
This type of query ensures that the client receives a complete answer to its request.
What are DNS zone types?
Portions of the domain name space in the DNS which are managed by a specific entity or administrator
Different zone types help organize and delegate control over various parts of the DNS.
What does a forward zone resolve?
Domain names to IP addresses
Forward zones are essential for translating user-friendly domain names into machine-readable IP addresses.
What kind of records does the forward zone contain?
A, AAAA, and MX
These records help direct traffic to the correct servers and services.
What does the reverse zone handle?
Maps IP addresses back to domain names
This process is crucial for identifying the domain associated with a specific IP address.
What zone type is used for reverse DNS lookup?
Reverse zone
Reverse lookups are often used for verification and troubleshooting.
What is the reverse zone often needed for?
Network troubleshooting and security verification
It helps in identifying potential issues or unauthorized access.
Does the Authoritative DNS zone need to query other sources?
No it has the final authority over its own records
Authoritative zones provide definitive answers without needing to refer to other servers.
Where has the information been obtained from with the non-authoritative zone?
From another server
Non-authoritative zones typically contain cached data from previous queries.
What kind of data is usually sourced from the non-authoritative DNS zone?
Cached from other previous queries
This data may not always be up-to-date or reliable.
What is the primary zone?
Main zone file where DNS records are stored and managed
The primary zone is crucial for maintaining the integrity of DNS records.
What does the primary zone allow?
Changes to DNS records directly
Administrators can modify records as needed in the primary zone.
What are secondary zones used for?
Fault tolerance, redundancy, and reduce loads/backup
Secondary zones help ensure availability and reliability of DNS services.
Can you make changes to DNS records in the secondary zone?
No, they are read-only copies of the primary zone
Secondary zones replicate the data but cannot be modified directly.
What does the DNS Security Extension (DNSSEC) do?
Enhances DNS security by providing authentication of DNS data
DNSSEC is vital for ensuring the integrity and authenticity of DNS responses.
What does DNSSEC use to validate DNS responses come from an authentic source?
Digital Signatures
Digital signatures help prevent spoofing and other forms of attack.
What is one example of a DNS-based attack?
Cache poisoning
Cache poisoning involves corrupting the cached responses of a DNS resolver.
What protocols are designed to encrypt DNS queries?
DoH (DNS over HTTPS) and DoT (DNS over TLS)
These protocols enhance privacy and security of DNS queries.
What kind of attacks does DoH and DoT ensure security against?
Eavesdropping and Man-in-the-middle attacks (On-path attack)
These protocols protect against unauthorized interception of DNS traffic.
