1.6 Explain the use and purpose of network services. Flashcards
Which DNS record type is responsible for identifying a primary authoritative name server?
Unselected
NS
SOA
MX
Root
The Start of Authority (SOA) record identifies a primary authoritative name server that maintains complete resource records for a zone.
A root is not a record type but is a server type. Root domain name system (DNS) servers have complete information about top-level domain servers.
A Mail Exchange (MX) record identifies an email server for the domain. An MX record must not point to a CNAME record.
An NS (Name Server) record identifies a server as a name server for a zone, but it does not indicate its authoritative status.
A user requests that a company web host have two different names for the same Internet protocol (IP) address. The user requests jobs.companyname.com and careers.companyname.com. Which domain name system (DNS) record does an IT tech configure to accomplish this?
CNAME
TXT
SRV
AAAA
A Canonical Name (CNAME) record is a Domain Name System (DNS) record used to represent an alias for a host. Aliases are used to give a host multiple names.
A Service (SRV) record is a DNS record which identifies a record that provides a network service or protocol. Properties of this record type include port and protocol.
A TXT record is used to store any free-form text needed to support other network services. An SPF record, for example, is a TXT record that is used to list the IP addresses or names of servers that are permitted to send email.
An AAAA record is used to resolve a host name to an Internet Protocol version 6 (IPv6) address.
A Windows Active Directory (AD) domain uses companyname.com. An external web server uses www.companyname.com. Users on the corporate network cannot reach the web server when using a www prefix. An IT engineer modifies which of the following to remedy the issue?
Third-party DNS
Internal DNS zone
External DNS zone
DNS forwarder
Internal domain name system (DNS) zones refer to the domains used on a private network. As the site uses the same domain name as AD, an A record for www needs to be created internally to point to the public web server address.
External domain name system (DNS) zones refer to records that Internet clients must be able to access.
A forwarder transmits a client query to find a host to another domain name system (DNS) server and routes the replies it gets back to the client.
Third-party domain name system (DNS) means that another organization is responsible for hosting records. Typically, this would be for external domains.
An engineer needs to update a DNS infrastructure with new host names. Which configuration does an engineer modify with host records that map to IP addresses?
Recursive lookups
Forward lookups
DNS caching
Time to live settings
Forward lookups use a forward lookup zone to return an IP address associated with a host name. In this case, an entry for the particular host was likely missed or contains a typo.
DNS caching occurs in both servers and client computers. Caching helps to speed the name resolution process by caching host names. If a cache cannot resolve a name, then a lookup is performed.
A recursive lookup means that if the queried server is not authoritative, it does take on the task of querying other name servers until it finds the requested record or times out.
Time to live (TTL) settings refer to the configuration of caching host names. When the TTL expires, the cache entry is invalid.
Users mention that a video conferencing service is not working properly. The service ties to the company domain name for business purposes. Which domain name system (DNS) record does the tech identify as incorrect?
TXT
CNAME
SRV
AAAA
A Service (SRV) record is a DNS record used to identify a record that is providing a network service or protocol. Properties of this record type include port and protocol.
A Canonical Name (CNAME) record is a Domain Name System (DNS) record used to represent an alias for a host.
A TXT record is used to store any free-form text that may be needed to support other network services. An SPF record, for example, is a TXT record that is used to list the IP addresses or names of servers that are permitted to send email.
An AAAA record is used to resolve a host name to an Internet Protocol version 6 (IPv6) address.
A server administrator configures a network’s internal DNS to set the records for all servers. Users mention that one server, in particular, is not reachable by name. What does the administrator investigate?
Forward lookups
DNS caching
Time to live settings
Recursive lookups
Forward lookups use a forward lookup zone to return an IP address associated with a host name. In this case, an entry for the particular host was likely missed or contains a typo.
DNS caching occurs in both servers and client computers. Caching helps to speed the name resolution process by caching host names. If a cache cannot resolve a name, then a lookup is performed.
A recursive lookup means that if the queried server is not authoritative, it does take on the task of querying other name servers until it finds the requested record or times out.
Time to live (TTL) settings refer to the configuration of caching host names. When the TTL expires, the cache entry is invalid.
A company has an Active Directory domain called specks.com. The company has an on-demand subscription for cloud services and wants to ensure their internal applications are accessible to their remote employees via their Fully Qualified Domain Names (FQDNs) in the cloud. The company will control all these services and applications. Which of the following will the company most likely be using throughout their organization? (Select all that apply.)
Cloud-hosted DNS server
Third-party DNS server
Internal DNS server
External DNS server
The company is using an internal DNS server because it controls all its services and applications. The DNS server will provide name resolution using FQDNs.
The company wants to extend its internal DNS services to the cloud and a cloud-hosted option is most appropriate option. The company can deploy a virtual DNS server that is accessible by its cloud users.
External DNS servers refers to an external DNS zone that Internet clients must be able to access. A company will most likely not have an external DNS server with a public IP address.
Most external DNS servers are managed by third-party organizations and are referred to as external DNS servers. These are usually owned and managed by another company.
A Windows Active Directory (AD) domain uses companyname.com. An external ftp server uses ftp.companyname.com. Users on the corporate network cannot reach the ftp server when using an ftp prefix. An IT engineer modifies which of the following to remedy the issue?
Internal DNS zone
Third-party DNS
External DNS zone
DNS forwarder
Internal domain name system (DNS) zones refer to the domains used on a private network. As the site uses the same domain name as AD, an A record for ftp needs to be created internally to point to the public ftp server address.
External domain name system (DNS) zones refer to records that Internet clients must be able to access.
A forwarder transmits a client query to find a host to another domain name system (DNS) server and routes the replies it gets back to the client.
Third-party domain name system (DNS) means that another organization is responsible for hosting records. Typically, this would be for external domains.
