I'm confused about virtualhosts and DNS. Apache2. 1

[SimonDavis]

Wonder if someone can clarify this, I've spent a while trying to pin it down.

I have a domain, (lets call it mydomain.com).

The DNS records for it all specify just mydomain.com, not

http://www.mydomain.com

or anything else.

I am innocently assuming then that any request for something on that domain will be forwarded to my server - but

http://www.mydomain

works fine, but anything else, say test.mydomain.com doesn't.

I have tried adding some virtualhosts, but to be honest it's confusing. Whatever I do,

http://www works,

others don't.

Is this a dns issue (and if so, why does

http://www work,

and others not), or am I maybe messing up the virtualhosts entries in the apache config file?

Thanks for reading!

 

[ericbrunson]

Each name you want to access the web server by must have a dns entry. They can share the same IP address or be aliases (CNAME records), but they all have to be in DNS. I think you will find that yourdomain.com and

http://www.yourdomain.com

are both in DNS.

Virt hosts work because in the request phase of the HTTP connection the browser sends the HTTP request:

GET /whatever.html HTTP/1.1

Then sends:

Host: whatever.yourdomain.com

Notice the GET doesn't specify the hostname, but the next line tells the web server what host it wants to talk to. That's why they can share an IP address. Note: SSL requires a dedicated, unshared IP address in Apache.

 

[SimonDavis]

OK - thanks for the reply, so I need to get the DNS entry changed (or even a new one) each time I add what I (maybe wrongly) call a subdomain, right?

I kind of suspected this, but the confusion is becuase I can't actually find the

http://www part

anywhere when browsing around DNS records. Would it make sense that maybe its my ISPs nameservers that do that part then?

Anyway, thanks a lot for your help!

 

[ericbrunson]

Yes, if you want to handle test.yourdomain.com as a different virtual host, you need to add it to DNS.

It could be your ISP, if you posted your domain I could tell you. It could be your browser. A lot of browsers will stick a .com after a hostname that doesn't have one and stick a

http://www in

front of a hostname if it can't get a reply from the host without it.

 

[SimonDavis]

OK, promise not to laugh . . .

http://www.bollockbrains.com

I make no apologies for the crappy wesite on it, I'm letting a friend practice his l33t HTML skills while I get my head around webservers!

Anything you could tell me would be interesting. Thanks.

 

[ericbrunson]

Your DNS providers, INTERNETTERS.NET, have a DNS entry for both bollockbrains.com and

http://www.bollockbrains.com.

That's why both work.

 

[SimonDavis]

Eric,

Thanks for the Info - would that mean I could have different sites on

http://www.bollockbrains.com

and just bollockbrains.com.

Strikes me as I'm writing this I should just try it and see . . .

Appreciate your input anyway, I am now just a little further down the road!

 

[SimonDavis]

(update, tried that, it works)