Order
order ordering
directory, .htaccess
The
ordering argument is one word (i.e., it is
not allowed to contain a space) and controls the order in which the
foregoing directives are applied. If two order
directives apply to the same host, the last one to be evaluated
prevails:
deny,allow
The deny directives are evaluated before the
allow directives. This is the default.
allow,deny
The allow directives are evaluated before the
denys, but the user will still be rejected if a
deny is encountered.
mutual-failure
Hosts that appear on the allow list and do not
appear on the deny list are allowed access.
We could say:
allow from all
which lets everyone in and is hardly worth writing, or we could say:
allow from 123.156 deny from all
As it stands, this denies everyone except those whose IP addresses
happen to start with 123.156. In other words,
allow is applied last and carries the day. If,
however, we changed the default order by saying:
order allow,deny allow from 123.156 deny from all
we effectively close the site because deny is now
applied last. It is also possible to use domain names, so that
instead of:
deny from 123.156.3.5
you could say:
deny from badguys.com
Although this has the advantage of keeping up with the Bad Guys as they move from one IP address to another, it also allows access by people who control the reverse-DNS mapping for their IP addresses.
A URL can be contain just part of the hostname. In this case, the
match is done on whole words from the right. That is,
allow
from
fred.com allows fred.com and
abc.fred.com, but not
not
fred.com.
Good intentions, however, are not enough: before conferring any trust in a set of access rules, you want to test them very thoroughly in private before exposing them to the world. Try the site with as many different browsers as you can muster: Netscape and MSIE can behave surprisingly differently. Having done that, try the site from a public-access terminal — in a library, for instance.