> #### General considerations

> Review the following information about HTTP rules and Web page redirection before you set up HTTP resource monitors.

> ##### HTTP rules

> HTTP monitors use a unique set of resource rules to monitor the status and content details of a Universal Resource Locator (URL). When enabled, the status rule can indicate whether:

> - The URL you are monitoring was redirected.
> - The GET method was successful and was accomplished within the time range you specified.

> Similarly, the content rule can also be enabled to indicate content details such as whether:

> - A hash value comparison should be performed.
> - A search should be performed on a given page for the search string you specify.

> For each schedule you define for a URL that you intend to monitor, you also define status and content rules to suit your specific URL monitoring needs. See the "Editing rules for the HTTP resource monitor" section for details about editing status rules and content rules.

> ##### Web page redirection

> When attempting to retrieve a web page, your client may be directed to a page other than the one initially requested.

> This situation can occur for the following reasons:

> - Redirection
> Redirection occurs when the server informs the client that it is being redirected, and sends the client to the new page. When redirection occurs within the context of using an HTTP Monitor, a redirection alert occurs if you have selected the Alert if URL was redirected option on the Edit status rule page.

> - Aliasing
> Aliasing occurs when the server sends the client to a different page without informing the client. The client believes that it has retrieved the Web page that was originally requested. Because the server does not inform the client that it has been sent to a different page, the HTTP Monitor cannot trigger redirection alerts, even if the Alert if URL was redirected option is selected on the Edit status rule page.

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