I access production and qa domain websites as follows :

Production : https://portal.mydomain.com

QA : https://portal-qa.mydomain.com

However, when I add www like the following :https://www.portal-qa.mydomain.com, I get "Web Page Not" available error on the browser.

Since I have been following the steps for generating CSR using OpenSSL as mentioned here

They have mentioned domain name as www.mydomain.com.


Is it okay if I use portal.mydomain.com and portal-qa.mydomain.com as my fully qualified domain name(FQDN) without using www for generating the CSR? Please advise.


If you have purchase a standard, single domain SSL certificate, then it will be for one domain, so you can only use it for domainname.com or www.domainname.com.

If you have purchased a wildcard or UCC certificate then it will allow either unlimited subdomains (in the case of a wildcard) or mulitple domains up to a certain number (in the case of UCC).


  • Yes, I will be going to purchase it for one domain only. I am wondering if not adding www to the Common Name would make any difference?
    – John
    Feb 3 '16 at 7:11
  • @John Steve is correct, most SSL certificates will cover one or the other, so most sites just redirect one to the other. That way you'll avoid issues with duplicate content as well. There are a few providers that issue SSL's that cover both, see this for more info about that. For the different subdomains (which actually www is considered to be as well), you'll need a UCC certificate. A cheap (free) alternative to all the above is just to use a CDN that offers a "flexible" SSL, such as CloudFlare.
    – dan
    Feb 3 '16 at 7:26
  • @dan I am planning to get domain validated certificate from Globalsign( AlphaSSL). Since we don't use www, I think it wouldn't make sense to use a service which uses both.
    – John
    Feb 3 '16 at 7:31
  • If you don't use www, there really is no need. For example, even Google redirects their non-www domain to www. Most do this to avoid from having to manage both, and to not confuse search engines. The reason to get one with both would be if you need to serve different content from both (such as for an intranet or application).
    – dan
    Feb 3 '16 at 7:38

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