subdomain vs. full domain

Question

In Linux/Apache does a subdomain have all the functionality of a normal domain?

For instance, can I have a www address, https address, and can I have email? Eg,

http://www.mysubdomain.mydomain.com and
https://www.mysubdomain.mydomain.com

http://mysubdomain.mydomain.com and
https://mysubdomain.mydomain.com

and,

[email protected]

Is this possible/practical?

Thanks,

Answer 1

It's possible, for example some universities use it to separate the departments (mail). For HTTPS you need a wildcard certificate if you want "trusted" connections.

Answer 2

There is actually no meaningful distinction between a hostname which happens to be a second-level domain and a hostname which has more parts than that. You can even have a machine at a top-level domain if you happen to be a small country or otherwise are able to create an A record for one.

So, "yes".

Answer 3

It's completely possible, as has been said. For myself, I don't think people make anything like enough use of subdomains; I use subdomains in my personal domain to separate my colo'ed box from my at-home machines, I've delegated another subdomain for a friend who wants a vanity domain but doesn't want to pay for a full registration, I've delegated yet another for attempts with dynamic DNS for friends who have home boxes and want to offer web service but don't want to have to email me when their ADSL IP changes.

Go for it.

Answer 4

In Linux/Apache does a subdomain have all the functionality of a normal domain?

Yes.

For instance, can I have a www address,

'www' is just a convention for a subdomain used to host a website.

https address

Only with a wildcard SSL certificate.

and can I have email?

Yes, but not via Apache (at least not directly). You need to run an SMTP server to receive mail. You then need to provide a way to access the received mail such as IMAP, POP or a webmail server (Apache can help with webmail).