You have a server that serves www, FTP, and mail. You need to access this server using www.yourname.com, ftp.yourname.com, and mail.yourname.com. You want to ensure an IP change results in the least number of other changes.What is the best solution?
- Create PTR records and point the IP address of the server back to www, ftp, and mail.
- Create an A record pointing to the server's IP address and create CNAME records for www, ftp, and mail and point those to the A record.
- Create an A record for www, ftp and mail, and point it to the ALIAS of the server.
- Create CNAME records for www, ftp, and mail and point those to the A record already provided to the instance by AWS.
Answer(s): B
Explanation:
There is no ALIAS record for an EC2 instance, CNAME records pointed to the A record provided by AWS won't work because if the IP changes, the A record will change also. A PTR record is not appropriate here and cannot point to more than one record. Having three CNAME records and one A record will result in only having to change the A record if the IP changes.