You are getting a DNS lookup error when trying to access any webpage that your local DNS server has no record for, what should you check?

You are getting a DNS lookup error when trying to access any webpage that your local DNS server has no record for, what should you check?

• The Forwarders on your DNS server
• The Reverse Lookup Zones on your DNS server
• The CNAME records on your DNS server for your host
• The Forward Lookup Zones on your DNS 

 

EXPLANATION

In Domain Name System (DNS) terms, a DNS forwarder is a DNS server that is used to forward DNS queries for external DNS names to DNS servers outside that network. It does it to DNS queries that it cannot resolve locally, meaning DNS queries
that it has no personal knowledge of. By using DNS forwarders you can improve the efficiency of name resolution for the computers in your network that query for DNS names outside your network (such as names on the Internet).

SOURCE

https://www.petri.com/best-practices-for-dns-forwarding

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With regards to DNS, what is the difference between an A record and an AAAA record?

With regards to DNS, what is the difference between an A record and an AAAA record?

• A record holds one IP for one host and AAAA record can hold up to four IPs for one host
• A record replies to one ping and AAAA record replies to four pings.
• A record is for the A-team and AAAA record is for a squad of A-teams.
• A record holds the IPv4 address and AAAA record holds the IPv6 address 

EXPLANATION

An A and AAAA record are both primary DNS records.  They associate a host name with a specific IP address, so that when a user types in a web address, their browser knows where to go for the actual website. An A record holds the IPv4 address and an AAAA record holds the IPv6 address.
More info here - https://en.wikipedia.org/wiki/List_of_DNS_record_types

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Which of the following CLI commands empties the DNS server cache in Windows Server?

Which of the following CLI commands empties the DNS server cache in Windows Server?

• ipconfig /flushdns
• Set-DNS -ClearCache
• Delete-DNSCache
• dnscmd /clearcache 

 EXPLANATION Dnscmd /clearcache clears the cache used for DNS server. Dnscmd is the tool used to manage DNS from the command line.
ipconfig /flushdns clears the DNS client cache. A DNS server has both caches but the client cache is the one used to provide name resolution for its own requests, not for other clients on the network.
Dnscmd TechNet article:
https://technet.microsoft.com/en-us/library/cc772069(v=ws.11).aspx

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In DNS terms what is the purpose of an "A" record?

In DNS terms what is the purpose of an "A" record?

• Resolves the MAC address of a host from its name
• Resolves the IP address of a host from its name
• Resolves the IP address of a host from the MAC address
• Resolves the Host name from its MAC address 

 

EXPLANATION

https://support.dnsimple.com/articles/a-record/
An A record maps a domain name to the IP address (IPv4) of the computer hosting the domain. Simply put, an A record is used to find the IP address of a computer connected to the internet from a name.

SOURCE

https://support.dnsimple.com/articles/a-record/

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