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| author | (no author) <(no author)@unknown> | 1999-06-18 18:39:23 +0000 |
|---|---|---|
| committer | (no author) <(no author)@unknown> | 1999-06-18 18:39:23 +0000 |
| commit | 6c87dba08027e687304e5a40fb0c950347243b15 (patch) | |
| tree | bc1dcecd450d9eda757c493d53a08e179271f49b /docs/manual/vhosts/host.html | |
| parent | db82a6637eb3e5e2afa9aca8a571c32187e072f4 (diff) | |
| download | httpd-dgaudet.tar.gz | |
This commit was manufactured by cvs2svn to create branch 'dgaudet'.dgaudet
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/dgaudet@83344 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'docs/manual/vhosts/host.html')
| -rw-r--r-- | docs/manual/vhosts/host.html | 172 |
1 files changed, 0 insertions, 172 deletions
diff --git a/docs/manual/vhosts/host.html b/docs/manual/vhosts/host.html deleted file mode 100644 index 5788676af8..0000000000 --- a/docs/manual/vhosts/host.html +++ /dev/null @@ -1,172 +0,0 @@ -<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> -<HTML><HEAD> -<TITLE>Apache non-IP Virtual Hosts</TITLE> -</HEAD> - -<!-- Background white, links blue (unvisited), navy (visited), red (active) --> -<BODY - BGCOLOR="#FFFFFF" - TEXT="#000000" - LINK="#0000FF" - VLINK="#000080" - ALINK="#FF0000" -> -<!--#include virtual="header.html" --> -<H1 ALIGN="CENTER">Apache non-IP Virtual Hosts</H1> - -<STRONG>See Also:</STRONG> -<A HREF="virtual-host.html">Virtual Host Support</A> - -<HR> - -<H2>What is a Virtual Host</H2> - -<P>The "Virtual Host" refers to the practice of maintaining more than -one server on one machine, as differentiated by their apparent -hostname. For example, it is often desirable for companies sharing a -web server to have their own domains, with web servers accessible as -<CODE>www.company1.com</CODE> and <CODE>www.company2.com</CODE>, -without requiring the user to know any extra path information.</P> - -<P>Apache was one of the first servers to support virtual hosts right -out of the box, but since the base <CODE>HTTP</CODE> (HyperText -Transport Protocol) standard does not allow any method for the server -to determine the hostname it is being addressed as, Apache's virtual -host support has required a separate IP address for each -server. Documentation on using this approach (which still works very -well) <A HREF="virtual-host.html">is available</A>. - -<P>While the approach described above works, with the available IP -address space growing smaller, and the number of domains increasing, -it is not the most elegant solution, and is hard to implement on some -machines. The <CODE>HTTP/1.1</CODE> protocol contains a method for the -server to identify what name it is being addressed as. Apache 1.1 and -later support this approach as well as the traditional -IP-address-per-hostname method.</P> - -<P>The benefits of using the new virtual host support is a practically -unlimited number of servers, ease of configuration and use, and -requires no additional hardware or software. The main disadvantage is -that the user's browser must support this part of the protocol. The -latest versions of many browsers (including Netscape Navigator 2.0 and -later) do, but many browsers, especially older ones, do not. This can -cause problems, although a possible solution is addressed below.</P> - -<H2>Using non-IP Virtual Hosts</H2> - -<P>Using the new virtual hosts is quite easy, and superficially looks -like the old method. You simply add to one of the Apache configuration -files (most likely <CODE>httpd.conf</CODE> or <CODE>srm.conf</CODE>) -code similar to the following:</P> -<PRE> - <VirtualHost www.apache.org> - ServerName www.apache.org - DocumentRoot /usr/web/apache - </VirtualHost> -</PRE> - -<P>Of course, any additional directives can (and should) be placed -into the <CODE><VirtualHost></CODE> section. To make this work, -all that is needed is to make sure that the <CODE>www.apache.org</CODE> -DNS entry points to the same IP address as the main -server. Optionally, you could simply use that IP address in the -<VirtualHost> entry.</P> - -<P>Additionally, many servers may wish to be accessible by more than -one name. For example, the Apache server might want to be accessible -as <CODE>apache.org</CODE>, or <CODE>ftp.apache.org</CODE>, assuming -the IP addresses pointed to the same server. In fact, one might want it -so that all addresses at <CODE>apache.org</CODE> were picked up by the -server. This is possible with the <CODE>ServerAlias</CODE> -directive, placed inside the <VirtualHost> section. For -example:</P> - -<PRE> - ServerAlias apache.org *.apache.org -</PRE> - -<P>Note that you can use <CODE>*</CODE> and <CODE>?</CODE> as wild-card -characters.</P> - -<P>You also might need ServerAlias if you are serving local users who -do not always include the domain name. For example, if local users are -familiar with typing "www" or "www.physics" then you will need to add -<CODE>ServerAlias www www.physics</CODE>. It isn't possible for the -server to know what domain the client uses for their name resolution -because the client doesn't provide that information in the request.</P> - -<H2>Security Considerations</H2> - -Apache allows all virtual hosts to be made accessible via the -<CODE>Host:</CODE> header through all IP interfaces, even those which -are configured to use different IP interfaces. For example, if the -configuration for <CODE>www.foo.com</CODE> contained a virtual host -section for <CODE>www.bar.com</CODE>, and <CODE>www.bar.com</CODE> was -a separate IP interface, such that -non-<CODE>Host:</CODE>-header-supporting browsers can use it, as -before with Apache 1.0. If a request is made to -<CODE>www.foo.com</CODE> and the request includes the header -<CODE>Host: www.bar.com</CODE>, a page from <CODE>www.bar.com</CODE> -will be sent. - -<P> - -This is a security concern if you are controlling access to a -particular server based on IP-layer controls, such as from within a -firewall or router. Let's say <CODE>www.bar.com</CODE> in the above -example was instead an intra-net server called -<CODE>private.foo.com</CODE>, and the router used by foo.com only let -internal users access <CODE>private.foo.com</CODE>. Obviously, -<CODE>Host:</CODE> header functionality now allows someone who has -access to <CODE>www.foo.com</CODE> to get -<CODE>private.foo.com</CODE>, if they send a <CODE>Host: -private.foo.com</CODE> header. It is important to note that this -condition exists only if you only implement this policy at the IP -layer - all security controls used by Apache (<EM>i.e.</EM>, <A -HREF="../mod/mod_access.html">allow, deny from,</A> <EM>etc.</EM>) are -consistently respected. - -<H2>Compatibility with Older Browsers</H2> - -<P>As mentioned earlier, a majority of browsers do not send the -required data for the new virtual hosts to work properly. These -browsers will always be sent to the main server's pages. There is a -workaround, albeit a slightly cumbersome one:</P> - -<P>To continue the <CODE>www.apache.org</CODE> example (Note: Apache's -web server does not actually function in this manner), we might use the -new <CODE>ServerPath</CODE> directive in the <CODE>www.apache.org</CODE> -virtual host, for example: - -<PRE> - ServerPath /apache -</PRE> -<P>What does this mean? It means that a request for any file beginning -with "<CODE>/apache</CODE>" will be looked for in the Apache -docs. This means that the pages can be accessed as -<CODE>http://www.apache.org/apache/</CODE> for all browsers, although -new browsers can also access it as -<CODE>http://www.apache.org/</CODE>.</P> - -<P>In order to make this work, put a link on your main server's page -to <CODE>http://www.apache.org/apache/</CODE> (Note: Do not use -<CODE>http://www.apache.org/</CODE> - this would create an endless -loop). Then, in the virtual host's pages, be sure to use either purely -relative links (<EM>e.g.</EM>, "<CODE>file.html</CODE>" or -"<CODE>../icons/image.gif</CODE>" or links containing the prefacing -<CODE>/apache/</CODE> -(<EM>e.g.</EM>, "<CODE>http://www.apache.org/apache/file.html</CODE>" or -"<CODE>/apache/docs/1.1/index.html</CODE>").</P> - -<P>This requires a bit of -discipline, but adherence to these guidelines will, for the most part, -ensure that your pages will work with all browsers, new and old. When -a new browser contacts <CODE>http://www.apache.org/</CODE>, they will -be directly taken to the Apache pages. Older browsers will be able to -click on the link from the main server, go to -<CODE>http://www.apache.org/apache/</CODE>, and then access the -pages.</P> - -<!--#include virtual="footer.html" --> -</BODY> -</HTML> |