3.4 Given a scenario, implement IPv4 and IPv6 network services.

Question 1

What is a DHCP reservation?

Answer 1

• Devices that will always receive the same IP address when it connects to the network.

Question 2

What is a DHCP scope?

Answer 2

• It is an IP address range that can be handed out to clients for use.

Question 3

What is a DHCP lease time?

Answer 3

• Can only use the address for a certain period of time and if they users doesn’t renew the lease, it will go back to the pool for another user to use.

Question 4

What is a DHCP option?

Answer 4

• A special field in the DCHP message
• Guided by DHCP RFC standard and referred to as “vendor extensions”.
• 254 usable options

Question 5

What is a DHCP relay/IP helper?

Answer 5

• Since most DHCP request sent as a broadcast cannot go past the router, some routers will allow a “relay” for this functionality that needs to be separately configured.

Question 6

What is a DHCP exclusion?

Question 7

What is a SLAAC?

Answer 7

• Stateless Address Autoconfiguration
• This automatically configures an IP address without DHCP server.
• DAD: Duplicate Address Detection.

Question 8

What is a DNSSEC?

Answer 8

• Domain Name Security Extension
• DNS responses from the server are digitally signed and a forgery would be easily identified
• Requires additional configurations on the DNS server.

Question 9

What is DoH?

Answer 9

• DNS over HTTPS
• Sends DNS Traffic in an HTTPS packet and looks like web server communication over TCP 443

Question 10

What is DoT?

Answer 10

• DNS over TLS
• Sends DNS traffic over TCP 853 and encrypts that information.

Question 11

What is record type (A)?

Answer 11

• Address
• Defines the IP address of a host.
• These are for IPv4 addresses

Question 12

What is record type (AAAA)?

Answer 12

• Defines the IP address of a host.
• These are for IPv6 addresses.

Question 13

What is record type (CNAME)

Answer 13

• Canonical Name
• A name is an alias of another name.
• One physical server, with multiple services.

Question 14

What is record type (MX)?

Answer 14

• Mail Exchange
• This determines the host name for the mail server; this isn’t an IP address, it’s a name.

Question 15

What is record type (TX)?

Answer 15

• Text
• Human-readable text information
• Useful for public information.
• SPF protocol (Sender Policy Framework): this prevents mail spoofing.
• DKIM (Domain Keys Identified Mail): digitally sign your outgoing mail

Question 16

What is record type (NS)?

Answer 16

• Nameserver
• It lists the name servers for a domain.

Question 17

What is record type (PTR)?

Answer 17

• Pointer
• The reverse of an A or AAAA record
• Give the server an IP address.

Question 18

What is a forward zone type?

Answer 18

• This provides the DNS server with an FQDN and the DNS server responds with an IP address.

Question 19

What is a reverse zone type?

Answer 19

• This provides the DNS server with an IP address and the DNS server responds with an FQDN.

Question 20

What is Authoritative DNS?

Answer 20

• The DNS server is the authority for the zone.
• TTL (Time to Live) is configured here.
• Very long TTL can cause problems if changes are made.

Question 21

What is Non-Authoritative DNS?

Answer 21

• Does not contain the zone source files; probably cached information.

Question 22

Primary vs. Secondary

Question 23

What is recursive DNS?

Answer 23

• Delegates the look-up to a DNS server.
• The DNS server does the work and reports back
• Large DNS cache provides a speed advantage.

Question 24

What is the host file’s relationship to DNS?

Answer 24

• Contains a list of IP addresses and host names with preferred resolutions.
• Some apps may not use the host file, the will rely on the DNS server as the primary source for information.

Question 25

What is NTP?

Answer 25

• Network Time Protocol
• Switches, routers firewalls, servers, workstations has its own clock that is synchronized.
• Need to have a server responsible for this function (UDP 123).

Question 26

What is PTP?

Answer 26

• Percision Time Protocol
• A hardware-based time synchronization that provides nanosecond granularity
• Often implemented as specialized hardware that can avoid delays from the operating system and applications.

Question 27

What is NTS?

Answer 27

• Network Time Security
• How do you know your NTP server response can be trusted (could cause DDoS)?
• This provides a level of authentication so you can validate the time is correct.

Question 28

What is DORA?

Answer 28

1. Discover: Find DHCP server
2. Offer: Get an offer from DHCP server.
3. Request: lock in the offer from the DHCP server
4. Acknowledge: DHCP server confirmation.

Question 29

What is NDP?

Answer 29

• Neighbor Discovery Protocol
• No broadcasts! Operates using multicast over ICMPv6
  Neighbor MAC Discovery

Question 30

What is RR?

Answer 30

• Resource Records
• The database records of domain name services.
• Over 30 record types.

Question 31

What is a SOA record type?

Answer 31

• Start of Authority
• Describes the DNS zone details.