Q1. What is the difference between CName and A record with example ?
CName makes one domain name an alias of another i.e all aliased domain gets all the subdomains and DNS records of the original.
Example of a CNAME record: “qiblah.whatsnew.ng CNAME dev.whatsnew.ng” where ‘dev.whatsnew.ng’ is A record listing an IP address, and ‘qiblah.whatsnew.ng’ points to ‘dev.whatsnew.ng’.
A record assigns an IP address to a domain or subdomain name in which no two A records refer to the same IP address.
Q2. When and where will you apply CName
When I want to have as many subdomains as I wish without having to specify the IP for every record i.e I will use CName if I have more services pointing to the same IP.
Q3.Do you know any restriction of CName ?
CNAMEs cannot change the HTTP default of 80 to any other port number.
It doesn’t allow fowarding of a domain to a specific web page.
It will NOT allow you to foward a domain to a specific web page. Use a webhop for that. Port numbers can be changed with webhops, as well; CNAMEs cannot change the HTTP default of 80 to any other port number.
Q4. Do you think CName is useful ?
Yes it’s, as I have to update only one record if there is a change of IP address.