AWS CloudWatch Scheduled Event and Lambda Function

Which of the following DNS record types is an alias?

A.

CNAME

B.

PTR

C.

NS

D.

SRV.

A.

The DNS (Domain Name System) is a system that translates domain names into IP addresses. DNS records are used to store information about domain names and their corresponding IP addresses.

Among the DNS record types, the CNAME (Canonical Name) record is an alias. A CNAME record maps an alias domain name to the canonical (real) domain name. When a client looks up the IP address of the alias domain name, the DNS server returns the IP address of the canonical domain name.

For example, suppose there is a web server with the canonical domain name "www.example.com" and an alias domain name "www.alias.com". To set up the alias, a CNAME record for "www.alias.com" would be created with a value of "www.example.com". This tells DNS servers that "www.alias.com" is an alias for "www.example.com".

The other DNS record types listed in the question are not aliases.

• The PTR (Pointer) record is used to map an IP address to a domain name, in the opposite direction of a forward DNS lookup.
• The NS (Name Server) record is used to identify the authoritative name servers for a domain.
• The SRV (Service) record is used to define the location of servers for specific services, such as LDAP or SIP.