Term
A TCP/IP system that resolves hostnames to IP addresses and vice-vera, along with other bindings like servers for a domain. (pg. 317)
A. FQDN
B. DHCP
C. NetBIOS
D. DNS |
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Definition
D. DNS (Domain Name System) is a powerful, extensible, flexible system that supports name resolutions on networks, from tiny in-house ones up to the entire Internet.
An FQDN (fully qualified domain name) is the complete DNS name of a system.
DHCP (Dynamic Host Configuration Protocol) is what allows client devices to obtain IP info from a DHCP server.
NetBIOS is an old, proprietary networking protocol from Microsoft that DNS supplanted. |
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Term
A special text file residing on every computer that is used to resolve DNS hostnames to IP addresses. (pg. 320)
A. hosts
B. DNS map
c. operator
D.index |
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Definition
A. The hosts file contained a list of IP addresses for every computer on the network, matched to the corresponding system names.
Our clinical computers use it to connect to Epic servers; using Notepad, open it from
C:\Windows\System32\drivers\etc to see an example! |
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Term
The DNS component that queries name servers and translates DNS names to IP addresses. (pg. 321)
A. DNS server
B. root server
C. resolver
D. zone |
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Definition
C. Resolver
DNS servers are the name servers that the resolvers query to get an IP address, and hold the actual name and IP DNS records in a zone.
DNS root servers form a system (aka the "root") of a global hierarchy that covers every name accessible on the public Internet.
A zone is the database where name servers hold hostnames and IP DNS records. |
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Term
Servers that are just below the DNS root in the global hierarchy that handle names such as .com, .org, .net. .edu., .gov, .mil, etc. (pg. 322)
A. TLD servers
B. name servers
C. HTTP servers
D. authoritative servers |
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Definition
| A. Top-level domain (TLD) servers delegate to domain-specific name servers that handle the 300 million+ names registered under each top-level domain. |
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Term
Networks that use DNS rely on a(n) ___, a tree structure for naming network resources so they interconnect but have unique names or paths within that network. (pg. 322)
A. linked list
B. master list
C. hierarchical name space
D. data table |
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Definition
| C. A hierarchal name space uses a root/folder/subfolder/file hierarchy; the C: drive of Windows is a good example. |
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Term
A complete DNS name, including the host name and all its domains, is called a(n) ___. (pg. 324)
A. root
B. fully qualified domain name (FQDN)
C. top-level domain (TLD) name
D. hierarchical name space |
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Definition
| B. An FQDN is written with the root on the far right, followed by the names of the domains (in order) added to the left of the root, and the host name on the far left. Each name is separated by a period. |
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Term
A(n) ___ attaches a piece of data to a name in the DNS tree, such as its IP address. (pg. 326)
A. file
B. host file
C. name server
D. record |
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Definition
A. Records store the names you see between the dots in a fully qualified domain name (FQDN).
A host file is from the ARPANET days and contained a list of IP addresses corresponding to system names.
A name server is software that responds to queries about DNS zones. |
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Term
A container for a single domain that gets filled with records. (pg. 326)
A. zone
B. hosts file
C. name space
D. root |
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Definition
A. A zone is a collection of records about a name in the DNS tree.
A host file is from the ARPANET days and contained a list of IP addresses corresponding to system names.
A name space is a tree structure for naming network resources so they interconnect but have unique names or paths within that network. DNS uses a hierarchical structure.
The root is the top of the DNS hierarchy in a network, with domains, subdomains and hosts under it. |
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Term
The DNS server that holds the primary zone file for a particular domain or domains. (p. 326)
A. authoritative name server
B. primary name server
C. root server
D. top-level domain server |
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Definition
A. A single name server can be authoritative for one or more domains.
The primary name server is where records are added, deleted and modified.
The root is the top of the DNS hierarchy in a network, with domains, subdomains and hosts under it.
Top-level domain (TLD) servers delegate to domain-specific name servers handle names such as .com and.org |
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Term
If one DNS server gets a new record, that record must propagate to all the name servers through a process called ___ (pg. 327).
A. live updating
B. zone transfer
C. record sync
D. domain parity |
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Definition
| B. If there are several servers supporting the same domain, they must talk to each other frequently. Every name sever for this domain must know the name and address of the primary name server as well as the name and address of every secondary name server. |
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Term
Secondary name servers regularly check a special value from the primary server called the ___ to see if there have been changes to the zone. (pg. 327)
A. record
B. serial field
C. resolver
D. zone transfer |
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Definition
| B. If a secondary server sees that its serial field is lower than the one on the primary server, it requests a zone transfer of the DNS zone from the primary server. |
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Term
| What is a reverse lookup? (pg. 328) |
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Definition
The process of converting an IP address back into a name.
A reverse lookup zone takes a network ID, reverses it, and adds a unique domaine called "in-addr.arpa" to create the zone. |
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Term
| What is the difference between forward and reverse lookup zones? (pg. 328) |
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Definition
Forward lookup enables a system to determine an IP address by knowing the FQDN; reverse lookup enables a system to determine an FQDN by knowing the IP address.
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Term
A cache used by Windows DNS clients to keep track of DNS information. (pg. 329)
A. host file
B. zone cage
C. resolver cache
D. lookup |
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Definition
C. The resolver cache is a memory area that includes recently resolved addresses. Getting an address locally is much more efficient than querying a remote server.
The host file stores addresses of other devices, but not resolved addresses.
Z(h)one cage is a reference to Tales of Graces f, the last RPG I played on the PS3.
The point of DNS is to lookup server or client names and addresses, but that's a verb! |
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Term
A lookup where one DNS server communicates with several other DNS servers to hunt down an IP address and return it to the client. (pg. 332)
A. inverted lookup
B. reverse lookup
C. recursive lookup
D. iterative lookup |
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Definition
C. In a recursive lookup, the resolver will query other servers as needed to answer the query. Once it has the IP information needed, the DNS server stores a copy of it in its cache and answers the client that made the request.
A reverse lookup is the process to get an FQDN from an IP address.
An iterative lookup is when the client communicates directly with each DNS server involved in the lookup.
No such thing as an inverted lookup |
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Term
A DNS query in which the client communicates directly with each DNS server involved in the lookup. (pg. 332)
A. independent
B. reverse
C. iterative
D. recursive |
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Definition
C. An iterative lookup is analogous to the client telling the DNS resolver to provide the address of the next DNS server in the process so the client can pursue the IP address on their own.
A reverse lookup is the process to get an FQDN from an IP address.
A recursive lookup is when a DNS server queries other DNS servers on behalf of the client.
Ain't no independent lookup. |
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Term
A feature of DNS servers that temporarily stores information about previous DNS lookups to speed up future requests. (pg. 334)
A. host file
B. resolver cache
C. zone
D. DNS cache |
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Definition
D. Servers acting as recursive resolvers cache the results of DNS queries to speed up future requests.
A host file contains a list of IP addresses corresponding to system names; it's a local file, and doesn't store information about previous DNS lookups.
A resolver cache refers to the memory area for the OS of a local machine to check for recently resolved addresses instead of consulting a DNS server.
A zone is a collection of records about a name in a DNS tree. |
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Term
The required record in every zone that defines the primary name server in charge of that zone. (pg. 336)
A. A
B. SOA
C. NS
D. CNAME |
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Definition
| B. The start of authority (SOA) record also includes parameters that control how secondary name servers check for updates to the zone file, such as the serial number which indicates whether the zone file has updates to fetch. |
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Term
A record that points to the server holding the records (zone) for a part of the DNS tree. (pg. 337)
A. MX
B. PTR
C. SOA
D. NS |
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Definition
| D. Name service (NS) records enable the name servers to know where to point the resolvers to find the authoritative name servers for a specific domain below them in the DNS hierarchy. |
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Term
A DNS record that maps a hostname to its IPv4 address. (pg. 339)
A. A
B. MX
C. CNAME
D. PTR |
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Definition
A. Individual hosts each get their own unique address (A) record.
MX records are used to determine where to send mail.
A CNAME record holds an FQDN, not an IP address.
A PTR record is like a reverse A record |
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Term
| What is the difference between A records and AAAA records? (pg. 339) |
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Definition
| A records hold IPv4 addresses for hosts, while AAAA records IPv6 addresses. |
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Term
This type of DNS record holds an FQDN instead of an IP address. (pg. 339)
A. SOA
B. CNAME
C. AAAA
D. TXT |
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Definition
B. A common use for a canonical name (CNAME) record is to provide an alias for another hostname. For instance, bucks.com references nba.com/bucks.
An SOA defines the primary name server in charge of the zone.
AAAA records store IPv6 info for hosts.
TXT records allow any text to be added to a zone. |
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Term
A DNS record that uses an IP address for its name and holds the FQDN of a host at that address. (pg. 340)
A. AAAA
B. A
C. PTR
D. SRV |
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Definition
C. A pointer (PTR) record is found only in reverse lookup zones and can only point a single IP address to a single FQDN.
They are the reverse of A and AAAA records, which map hostnames to IPv4 and IPv6 addresses.
An SRV is a record that supports any type of server. |
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Term
The DNS record that SMTP servers use to determine where to send mail. (pg. 340)
A. MX
B. SRV
C. POP3
D. IMAP |
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Definition
A. A mail exchange (MX) record holds the FQDN of the server that handles mail for the domain.
An SRV record is a generic one that supports any type of server, not exclusively mail servers like MX.
POP3 and IMAP are email protocols, not DNS record types. |
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Term
A DNS record that associates servers for individual protocols with a domain. (pg. 341)
A. A
B. SRV
C. TXT
D. SOA |
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Definition
B. Service (SRV) records specify a host, port, protocol and other details for a specific service.
An A record maps hostnames to IPv4 and IPv6 addresses.
A TXT record is a freeform tyype of record that allows any text to be added to a zone.
An SOA record defines the primary name server in charge of a zone. |
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Term
A freeform type of record that has become popular in helping to secure against e-mail spoofing. (pg. 342)
A. SRV
B. TXT
C. TTL
D. IMAP |
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Definition
B. A text (TXT) record allows any text string to be added to a zone.
SRV records are used by SMTP servers to determine where to send mail, not for security purposes.
TTL stands for "Time to live", as in the number of hops a packet can make before its discarded.
IMAP is an email protocol, not a DNS record type.
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Term
What is the command to eliminate any DNS caches on a local computer? (pg. 343)
A. ipconfig /release
B. ipconfig /flushdns
C. nslookup
D. sudo systemd-resolve -flush-caches |
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Definition
B. ipconfig /flushdns is the command for Windows, while sudo systemd-resolve -flush-caches is the command for Linux
nslookup (Name Server lookup) enables DNS server queries to determine if a DNS server is active.
ipconfig /release releases and renews the computer's IP address. |
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Term
The protocol that enables DNS servers to get automatic updates of IP addresses of computers in their forward lookup zones. (pg. 343)
A. DNSSEC
B. EDNS
C. DHCP
D. DDNS |
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Definition
D. Active Directory leans heavily on Dynamic DNS (DDNS), using it for the DHCP server to talk to the DNS router.
DNSSEC is a security protocol that is implemented through EDNS.
DHCP is a protocol that enables a DHCP server to set TCP/IP settings automatically for a client. |
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