[users@httpd] Host header field: How is it enforced or not at all?

[Khoa Nguyen <khoa.coffee@xxxxxxxxx>]

Hi,

I don't quite understand the use of the Host: header field in HTTP 1.1
request. For example, I wrote a simple script to connect to
www.google.com on port 80. After the connection, I send the following
GET request:

GET / HTTP/1.1
Host: whatever.com
...

The web server doesn't seem to care what I put in the Host field and
always returns the google home page. Is this behaviour acceptable? Why
a HTTP 1.1 web server insists on the presence of a Host field but
doesn't seem to do any kind of checking on it?

Thanks,
Khoa