Method 2: URL rewriting to direct requests for CDN content

URL rewriting defined

URL rewriting is a technique used to change links in Web pages to direct requests to a different location. With URL rewriting, a new domain is created for a content provider. The GRM DNS server does not take over the DNS services for an existing authoritative DNS nameserver, as is the case with method 1.

URL rewriting is used by CDNs that host content for a content provider so that cacheable content flows through the CDN. In this case, instead of the content provider changing its DNS to support content flowing through the CDN, the CDN asks the content provider to change the URLs in the Web pages to URLs over which the CDN has control. The CDN can then configure its DNS with the authoritative zones that it needs.

Configuration overview

The following table provides an overview of the DNS-related steps required to complete GRM configuration if the GRM server handles only specific domains within the CDN namespace; that is, the content provider uses URL rewriting to direct client requests for CDN content.

Step	Action
1	Set up the DNS nameserver that is to rewrite the host name to be authoritative for the domains controlled by the CDN.
2	Run the setup program on the GRM server and assign a permanent IP address when prompted.
3	Install the GRM license on the GRM server. See the Appliance Manager online Help for instructions.
4	Set up a method for host-name rewriting to handle cache misses for CDN content. See Planning for handling cache misses for CDN content.
5	Test the connectivity to the back-end DNS nameserver.
6	Continue the GRM configuration. See the Appliance Manager online Help for instructions.